How to find conflicting viewpoints in chemistry - ACT Science
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During digestion, the energy in food is converted to energy the body can use. Scientists use calorimetry experiments to measure the calories, or energy, provided by food when it is digested or burned.
The relationship used to find the heat transferred energy 
is given by 
, where 
is the mass of the material, 
is the given specific heat capacity, and 
is the change in temperature of the material.
In this experiment, food was burned over a Bunsen burner under a can of 200 ml of water. The temperature change of the water and mass change of the food can be used to determine the calories in four different food items.
Table 1 shows the values of the change of mass of the food items, the change in temperature of the water and the energy. Table 2 shows the energy to mass ratio of three of those food items.
Table 1
Roasted Peanut Peanut Cracker Cheese Puff
Water Temp. Initial 23.9 °C 33.2 °C 40.3 °C 53.9 °C
Water Temp. Final 30.0 °C 40.9 °C 55.9 °C 62.8 °C
Food Mass Initial 0.69 g 0.61 g 3.21 g 1.22 g
Food Mass Final 0.38 g 0.21 g 0.91 g 0.48 g
Energy 1.22 Cal 1.54 Cal 3.12 Cal 1.78 Cal
Table 2
Sample Energy to Mass Ratio (Cal/g)
1 1.36
2 3.93
3 2.40
Based on the results shown in Table 1 from the experiment, what is the relationship between the mass change of the food sample and the calories in the food?
During digestion, the energy in food is converted to energy the body can use. Scientists use calorimetry experiments to measure the calories, or energy, provided by food when it is digested or burned.
The relationship used to find the heat transferred energy
In this experiment, food was burned over a Bunsen burner under a can of 200 ml of water. The temperature change of the water and mass change of the food can be used to determine the calories in four different food items.
Table 1 shows the values of the change of mass of the food items, the change in temperature of the water and the energy. Table 2 shows the energy to mass ratio of three of those food items.
Table 1
Roasted Peanut Peanut Cracker Cheese Puff
Water Temp. Initial 23.9 °C 33.2 °C 40.3 °C 53.9 °C
Water Temp. Final 30.0 °C 40.9 °C 55.9 °C 62.8 °C
Food Mass Initial 0.69 g 0.61 g 3.21 g 1.22 g
Food Mass Final 0.38 g 0.21 g 0.91 g 0.48 g
Energy 1.22 Cal 1.54 Cal 3.12 Cal 1.78 Cal
Table 2
Sample Energy to Mass Ratio (Cal/g)
1 1.36
2 3.93
3 2.40
Based on the results shown in Table 1 from the experiment, what is the relationship between the mass change of the food sample and the calories in the food?
Given the information in Table 1 along with the equation to calculate heat energy, one can see that mass change and energy are directly proportional. That is that as mass change increases, so does the energy.
Given the information in Table 1 along with the equation to calculate heat energy, one can see that mass change and energy are directly proportional. That is that as mass change increases, so does the energy.
Compare your answer with the correct one above
Two students are studying hydrocarbon combustion, or the burning of compounds containing carbon and hydrogen in the presence of oxygen gas. Both students express their views on this phenomenon.
Student 1: Hydrocarbons are high in energy and therefore naturally burn in order to release that energy. That energy is released in the form of light and heat. If water is thrown onto a fire, it will extinguish it because it cuts the combustion from the oxygen gas required for it to burn.
Student 2: Hydrocarbons are compounds at a greater energy state than the compounds produced when they burn. This excess energy changes to heat when hydrocarbons burn. Lastly, hydrocarbons require a spark to initiate the combustion.
Which of the following statements would both students be most likely to agree?
Two students are studying hydrocarbon combustion, or the burning of compounds containing carbon and hydrogen in the presence of oxygen gas. Both students express their views on this phenomenon.
Student 1: Hydrocarbons are high in energy and therefore naturally burn in order to release that energy. That energy is released in the form of light and heat. If water is thrown onto a fire, it will extinguish it because it cuts the combustion from the oxygen gas required for it to burn.
Student 2: Hydrocarbons are compounds at a greater energy state than the compounds produced when they burn. This excess energy changes to heat when hydrocarbons burn. Lastly, hydrocarbons require a spark to initiate the combustion.
Which of the following statements would both students be most likely to agree?
The correct answer is that hydrocarbons are high energy compounds. The other answers are not statements explicitly expressed by both students.
The correct answer is that hydrocarbons are high energy compounds. The other answers are not statements explicitly expressed by both students.
Compare your answer with the correct one above
Two students are studying hydrocarbon combustion, or the burning of compounds containing carbon and hydrogen in the presence of oxygen gas. Both scientists express their views on this phenomenon.
Student 1: Hydrocarbons are high in energy and therefore naturally burn in order to release that energy. That energy is released in the form of light and heat. If water is thrown onto a fire, it will extinguish it because it cuts the combustion from the oxygen gas required for it to burn.
Student 2: Hydrocarbons are compounds at a greater energy state than the compounds produced when they burn. This excess energy changes to heat when hydrocarbons burn. Lastly, hydrocarbons require a spark to initiate the combustion.
Which of the following statements would Student 2 be most likely to agree with and not Student 1?
Two students are studying hydrocarbon combustion, or the burning of compounds containing carbon and hydrogen in the presence of oxygen gas. Both scientists express their views on this phenomenon.
Student 1: Hydrocarbons are high in energy and therefore naturally burn in order to release that energy. That energy is released in the form of light and heat. If water is thrown onto a fire, it will extinguish it because it cuts the combustion from the oxygen gas required for it to burn.
Student 2: Hydrocarbons are compounds at a greater energy state than the compounds produced when they burn. This excess energy changes to heat when hydrocarbons burn. Lastly, hydrocarbons require a spark to initiate the combustion.
Which of the following statements would Student 2 be most likely to agree with and not Student 1?
The correct answer is that hydrocarbons require an initial amount of energy for combustion to occur. This is the only answer that Student 2 explicitly states and that Student 1 either does not mention or contradict.
The correct answer is that hydrocarbons require an initial amount of energy for combustion to occur. This is the only answer that Student 2 explicitly states and that Student 1 either does not mention or contradict.
Compare your answer with the correct one above
There are two types of forces that occur with all substances on Earth. Intramolecular forces occur between atoms in a molecule, while intermolecular forces occur between neighboring molecules. Intermolecular forces can be dipole-dipole forces, hydrogen bonding, or London dispersion forces.
Professor 1:
Water molecules represent an example of hydrogen bonding due to the attraction between the hydrogen atoms and the oxygen atoms in the molecule. This strong dipole-dipole occurs due to lone pairs present on such atoms as Fluorine, Nitrogen, and Oxygen, which are able to pair more closely to the hydrogen atom in another nearby molecule. Water can be present in a solid, liquid, or gaseous state on Earth depending on the competition between the strength of intermolecular bonds and the thermal energy of the system. In 1873, a Dutch scientist, Van der Waals derived an equation that included both the force of attraction between the particles of a gas and the volume of the particles at high pressures. This equation led to a better fit for experimental data than the Ideal Gas Law.
Professor 2:
Water is the only substance on Earth that we routinely encounter as a solid, liquid, and gas. At low temperatures, the water molecules lock into a rigid structure, but as the temperature increases, the average kinetic energy of the water molecules increases and the molecules are able to move more creating its other natural states of matter. The higher the temperature, the more likely water is to be a gas. Water is proof of the kinetic theory, which assumes that there is no force of attraction between the particles of the gas state. The best fit for experimental data involving water in a gaseous form is found by using the Ideal Gas Law, since there is no interaction between the gaseous molecules. This law accounts for all of the forces that occur with gases on Earth.
Which of the following statements is professor 1 most likely to agree with?
There are two types of forces that occur with all substances on Earth. Intramolecular forces occur between atoms in a molecule, while intermolecular forces occur between neighboring molecules. Intermolecular forces can be dipole-dipole forces, hydrogen bonding, or London dispersion forces.
Professor 1:
Water molecules represent an example of hydrogen bonding due to the attraction between the hydrogen atoms and the oxygen atoms in the molecule. This strong dipole-dipole occurs due to lone pairs present on such atoms as Fluorine, Nitrogen, and Oxygen, which are able to pair more closely to the hydrogen atom in another nearby molecule. Water can be present in a solid, liquid, or gaseous state on Earth depending on the competition between the strength of intermolecular bonds and the thermal energy of the system. In 1873, a Dutch scientist, Van der Waals derived an equation that included both the force of attraction between the particles of a gas and the volume of the particles at high pressures. This equation led to a better fit for experimental data than the Ideal Gas Law.
Professor 2:
Water is the only substance on Earth that we routinely encounter as a solid, liquid, and gas. At low temperatures, the water molecules lock into a rigid structure, but as the temperature increases, the average kinetic energy of the water molecules increases and the molecules are able to move more creating its other natural states of matter. The higher the temperature, the more likely water is to be a gas. Water is proof of the kinetic theory, which assumes that there is no force of attraction between the particles of the gas state. The best fit for experimental data involving water in a gaseous form is found by using the Ideal Gas Law, since there is no interaction between the gaseous molecules. This law accounts for all of the forces that occur with gases on Earth.
Which of the following statements is professor 1 most likely to agree with?
Professor 1 states that "In 1873, a Dutch scientist, Van der Waals derived an equation that... led to a better fit for experimental data than the Ideal Gas Law." This shows that the correct answer is "Van der Waals is responsible for finding a better method to simulate experimental data involving gases on Earth."
Additionally, "The higher the temperature, the more likely water is to be a gas." and "The Ideal Gas Law is the best way to simulate experimental data involving gases on Earth." are statements that match up with what professor 2 said in his statement. Finally, professor 1 states that "Water molecules represent AN example of hydrogen bonding" implying that water is one of many examples present.
Professor 1 states that "In 1873, a Dutch scientist, Van der Waals derived an equation that... led to a better fit for experimental data than the Ideal Gas Law." This shows that the correct answer is "Van der Waals is responsible for finding a better method to simulate experimental data involving gases on Earth."
Additionally, "The higher the temperature, the more likely water is to be a gas." and "The Ideal Gas Law is the best way to simulate experimental data involving gases on Earth." are statements that match up with what professor 2 said in his statement. Finally, professor 1 states that "Water molecules represent AN example of hydrogen bonding" implying that water is one of many examples present.
Compare your answer with the correct one above
There are two types of forces that occur with all substances on Earth. Intramolecular forces occur between atoms in a molecule, while intermolecular forces occur between neighboring molecules. Intermolecular forces can be dipole-dipole forces, hydrogen bonding, or London dispersion forces.
Professor 1:
Water molecules represent an example of hydrogen bonding due to the attraction between the hydrogen atoms and the oxygen atoms in the molecule. This strong dipole-dipole occurs due to lone pairs present on such atoms as Fluorine, Nitrogen, and Oxygen, which are able to pair more closely to the hydrogen atom in another nearby molecule. Water can be present in a solid, liquid, or gaseous state on Earth depending on the competition between the strength of intermolecular bonds and the thermal energy of the system. In 1873, a Dutch scientist, Van der Waals derived an equation that included both the force of attraction between the particles of a gas and the volume of the particles at high pressures. This equation led to a better fit for experimental data than the Ideal Gas Law.
Professor 2:
Water is the only substance on Earth that we routinely encounter as a solid, liquid, and gas. At low temperatures, the water molecules lock into a rigid structure, but as the temperature increases, the average kinetic energy of the water molecules increases and the molecules are able to move more creating its other natural states of matter. The higher the temperature, the more likely water is to be a gas. Water is proof of the kinetic theory, which assumes that there is no force of attraction between the particles of the gas state. The best fit for experimental data involving water in a gaseous form is found by using the Ideal Gas Law, since there is no interaction between the gaseous molecules. This law accounts for all of the forces that occur with gases on Earth.
Which of the following statements would professor 2 agree with?
There are two types of forces that occur with all substances on Earth. Intramolecular forces occur between atoms in a molecule, while intermolecular forces occur between neighboring molecules. Intermolecular forces can be dipole-dipole forces, hydrogen bonding, or London dispersion forces.
Professor 1:
Water molecules represent an example of hydrogen bonding due to the attraction between the hydrogen atoms and the oxygen atoms in the molecule. This strong dipole-dipole occurs due to lone pairs present on such atoms as Fluorine, Nitrogen, and Oxygen, which are able to pair more closely to the hydrogen atom in another nearby molecule. Water can be present in a solid, liquid, or gaseous state on Earth depending on the competition between the strength of intermolecular bonds and the thermal energy of the system. In 1873, a Dutch scientist, Van der Waals derived an equation that included both the force of attraction between the particles of a gas and the volume of the particles at high pressures. This equation led to a better fit for experimental data than the Ideal Gas Law.
Professor 2:
Water is the only substance on Earth that we routinely encounter as a solid, liquid, and gas. At low temperatures, the water molecules lock into a rigid structure, but as the temperature increases, the average kinetic energy of the water molecules increases and the molecules are able to move more creating its other natural states of matter. The higher the temperature, the more likely water is to be a gas. Water is proof of the kinetic theory, which assumes that there is no force of attraction between the particles of the gas state. The best fit for experimental data involving water in a gaseous form is found by using the Ideal Gas Law, since there is no interaction between the gaseous molecules. This law accounts for all of the forces that occur with gases on Earth.
Which of the following statements would professor 2 agree with?
Professor 2 states "The best fit for experimental data involving water in a gaseous form is found by using the Ideal Gas Law" so the correct answer is "The Ideal Gas Law most closely mirrors the gas interactions that occur in nature."
Additionally, "Van der Waals' equation most closely mirrors the gas interactions that occur in nature." and "The state of water is dependent upon the strength of intramolecular forces and the thermal energy present in the system." are both statements that match up with the first professor's statements. Finally, professor 2 states "The higher the temperature, the more likely water is to be a gas" , not "At low temperatures, water is present as a gas."
Professor 2 states "The best fit for experimental data involving water in a gaseous form is found by using the Ideal Gas Law" so the correct answer is "The Ideal Gas Law most closely mirrors the gas interactions that occur in nature."
Additionally, "Van der Waals' equation most closely mirrors the gas interactions that occur in nature." and "The state of water is dependent upon the strength of intramolecular forces and the thermal energy present in the system." are both statements that match up with the first professor's statements. Finally, professor 2 states "The higher the temperature, the more likely water is to be a gas" , not "At low temperatures, water is present as a gas."
Compare your answer with the correct one above
There are two types of forces that occur with all substances on Earth. Intramolecular forces occur between atoms in a molecule, while intermolecular forces occur between neighboring molecules. Intermolecular forces can be dipole-dipole forces, hydrogen bonding, or London dispersion forces.
Professor 1:
Water molecules represent an example of hydrogen bonding due to the attraction between the hydrogen atoms and the oxygen atoms in the molecule. This strong dipole-dipole occurs due to lone pairs present on such atoms as Fluorine, Nitrogen, and Oxygen, which are able to pair more closely to the hydrogen atom in another nearby molecule. Water can be present in a solid, liquid, or gaseous state on Earth depending on the competition between the strength of intermolecular bonds and the thermal energy of the system. In 1873, a Dutch scientist, Van der Waals derived an equation that included both the force of attraction between the particles of a gas and the volume of the particles at high pressures. This equation led to a better fit for experimental data than the Ideal Gas Law.
Professor 2:
Water is the only substance on Earth that we routinely encounter as a solid, liquid, and gas. At low temperatures, the water molecules lock into a rigid structure, but as the temperature increases, the average kinetic energy of the water molecules increases and the molecules are able to move more creating its other natural states of matter. The higher the temperature, the more likely water is to be a gas. Water is proof of the kinetic theory, which assumes that there is no force of attraction between the particles of the gas state. The best fit for experimental data involving water in a gaseous form is found by using the Ideal Gas Law, since there is no interaction between the gaseous molecules. This law accounts for all of the forces that occur with gases on Earth.
With which of the following statements would both professors agree?
There are two types of forces that occur with all substances on Earth. Intramolecular forces occur between atoms in a molecule, while intermolecular forces occur between neighboring molecules. Intermolecular forces can be dipole-dipole forces, hydrogen bonding, or London dispersion forces.
Professor 1:
Water molecules represent an example of hydrogen bonding due to the attraction between the hydrogen atoms and the oxygen atoms in the molecule. This strong dipole-dipole occurs due to lone pairs present on such atoms as Fluorine, Nitrogen, and Oxygen, which are able to pair more closely to the hydrogen atom in another nearby molecule. Water can be present in a solid, liquid, or gaseous state on Earth depending on the competition between the strength of intermolecular bonds and the thermal energy of the system. In 1873, a Dutch scientist, Van der Waals derived an equation that included both the force of attraction between the particles of a gas and the volume of the particles at high pressures. This equation led to a better fit for experimental data than the Ideal Gas Law.
Professor 2:
Water is the only substance on Earth that we routinely encounter as a solid, liquid, and gas. At low temperatures, the water molecules lock into a rigid structure, but as the temperature increases, the average kinetic energy of the water molecules increases and the molecules are able to move more creating its other natural states of matter. The higher the temperature, the more likely water is to be a gas. Water is proof of the kinetic theory, which assumes that there is no force of attraction between the particles of the gas state. The best fit for experimental data involving water in a gaseous form is found by using the Ideal Gas Law, since there is no interaction between the gaseous molecules. This law accounts for all of the forces that occur with gases on Earth.
With which of the following statements would both professors agree?
Both professors mention the Ideal Gas Law as a method used to mirror experimental data using a math equation. Though professor 1 prefers using the Van der Waals' equation, he still mentions the Ideal Gas Law as the traditional option used.
Both professors mention the Ideal Gas Law as a method used to mirror experimental data using a math equation. Though professor 1 prefers using the Van der Waals' equation, he still mentions the Ideal Gas Law as the traditional option used.
Compare your answer with the correct one above
There are two types of forces that occur with all substances on Earth. Intramolecular forces occur between atoms in a molecule, while intermolecular forces occur between neighboring molecules. Intermolecular forces can be dipole-dipole forces, hydrogen bonding, or London dispersion forces.
Professor 1:
Water molecules represent an example of hydrogen bonding due to the attraction between the hydrogen atoms and the oxygen atoms in the molecule. This strong dipole-dipole occurs due to lone pairs present on such atoms as Fluorine, Nitrogen, and Oxygen, which are able to pair more closely to the hydrogen atom in another nearby molecule. Water can be present in a solid, liquid, or gaseous state on Earth depending on the competition between the strength of intermolecular bonds and the thermal energy of the system. In 1873, a Dutch scientist, Van der Waals derived an equation that included both the force of attraction between the particles of a gas and the volume of the particles at high pressures. This equation led to a better fit for experimental data than the Ideal Gas Law.
Professor 2:
Water is the only substance on Earth that we routinely encounter as a solid, liquid, and gas. At low temperatures, the water molecules lock into a rigid structure, but as the temperature increases, the average kinetic energy of the water molecules increases and the molecules are able to move more creating its other natural states of matter. The higher the temperature, the more likely water is to be a gas. Water is proof of the kinetic theory, which assumes that there is no force of attraction between the particles of the gas state. The best fit for experimental data involving water in a gaseous form is found by using the Ideal Gas Law, since there is no interaction between the gaseous molecules. This law accounts for all of the forces that occur with gases on Earth.
Which statement would both professors agree with?
There are two types of forces that occur with all substances on Earth. Intramolecular forces occur between atoms in a molecule, while intermolecular forces occur between neighboring molecules. Intermolecular forces can be dipole-dipole forces, hydrogen bonding, or London dispersion forces.
Professor 1:
Water molecules represent an example of hydrogen bonding due to the attraction between the hydrogen atoms and the oxygen atoms in the molecule. This strong dipole-dipole occurs due to lone pairs present on such atoms as Fluorine, Nitrogen, and Oxygen, which are able to pair more closely to the hydrogen atom in another nearby molecule. Water can be present in a solid, liquid, or gaseous state on Earth depending on the competition between the strength of intermolecular bonds and the thermal energy of the system. In 1873, a Dutch scientist, Van der Waals derived an equation that included both the force of attraction between the particles of a gas and the volume of the particles at high pressures. This equation led to a better fit for experimental data than the Ideal Gas Law.
Professor 2:
Water is the only substance on Earth that we routinely encounter as a solid, liquid, and gas. At low temperatures, the water molecules lock into a rigid structure, but as the temperature increases, the average kinetic energy of the water molecules increases and the molecules are able to move more creating its other natural states of matter. The higher the temperature, the more likely water is to be a gas. Water is proof of the kinetic theory, which assumes that there is no force of attraction between the particles of the gas state. The best fit for experimental data involving water in a gaseous form is found by using the Ideal Gas Law, since there is no interaction between the gaseous molecules. This law accounts for all of the forces that occur with gases on Earth.
Which statement would both professors agree with?
Both professors mention the fact that water is encountered on Earth as a solid, liquid, and gas. The other answers are either only mentioned by one professor or neither professor.
Both professors mention the fact that water is encountered on Earth as a solid, liquid, and gas. The other answers are either only mentioned by one professor or neither professor.
Compare your answer with the correct one above
There are two types of forces that occur with all substances on Earth. Intramolecular forces occur between atoms in a molecule, while intermolecular forces occur between neighboring molecules. Intermolecular forces can be dipole-dipole forces, hydrogen bonding, or London dispersion forces.
Professor 1:
Water molecules represent an example of hydrogen bonding due to the attraction between the hydrogen atoms and the oxygen atoms in the molecule. This strong dipole-dipole occurs due to lone pairs present on such atoms as Fluorine, Nitrogen, and Oxygen, which are able to pair more closely to the hydrogen atom in another nearby molecule. Water can be present in a solid, liquid, or gaseous state on Earth depending on the competition between the strength of intermolecular bonds and the thermal energy of the system. In 1873, a Dutch scientist, Van der Waals derived an equation that included both the force of attraction between the particles of a gas and the volume of the particles at high pressures. This equation led to a better fit for experimental data than the Ideal Gas Law.
Professor 2:
Water is the only substance on Earth that we routinely encounter as a solid, liquid, and gas. At low temperatures, the water molecules lock into a rigid structure, but as the temperature increases, the average kinetic energy of the water molecules increases and the molecules are able to move more creating its other natural states of matter. The higher the temperature, the more likely water is to be a gas. Water is proof of the kinetic theory, which assumes that there is no force of attraction between the particles of the gas state. The best fit for experimental data involving water in a gaseous form is found by using the Ideal Gas Law, since there is no interaction between the gaseous molecules. This law accounts for all of the forces that occur with gases on Earth.
Which of these statements made by professor 2 is not contradicted by professor 1?
There are two types of forces that occur with all substances on Earth. Intramolecular forces occur between atoms in a molecule, while intermolecular forces occur between neighboring molecules. Intermolecular forces can be dipole-dipole forces, hydrogen bonding, or London dispersion forces.
Professor 1:
Water molecules represent an example of hydrogen bonding due to the attraction between the hydrogen atoms and the oxygen atoms in the molecule. This strong dipole-dipole occurs due to lone pairs present on such atoms as Fluorine, Nitrogen, and Oxygen, which are able to pair more closely to the hydrogen atom in another nearby molecule. Water can be present in a solid, liquid, or gaseous state on Earth depending on the competition between the strength of intermolecular bonds and the thermal energy of the system. In 1873, a Dutch scientist, Van der Waals derived an equation that included both the force of attraction between the particles of a gas and the volume of the particles at high pressures. This equation led to a better fit for experimental data than the Ideal Gas Law.
Professor 2:
Water is the only substance on Earth that we routinely encounter as a solid, liquid, and gas. At low temperatures, the water molecules lock into a rigid structure, but as the temperature increases, the average kinetic energy of the water molecules increases and the molecules are able to move more creating its other natural states of matter. The higher the temperature, the more likely water is to be a gas. Water is proof of the kinetic theory, which assumes that there is no force of attraction between the particles of the gas state. The best fit for experimental data involving water in a gaseous form is found by using the Ideal Gas Law, since there is no interaction between the gaseous molecules. This law accounts for all of the forces that occur with gases on Earth.
Which of these statements made by professor 2 is not contradicted by professor 1?
All of the other answer choices are proven wrong with the first professor's statements. The only choice that involves a statement only dicussed by professor 2 is "As temperature increases, the average kinetic energy of the water molecules increases."
All of the other answer choices are proven wrong with the first professor's statements. The only choice that involves a statement only dicussed by professor 2 is "As temperature increases, the average kinetic energy of the water molecules increases."
Compare your answer with the correct one above
There are two types of forces that occur with all substances on Earth. Intramolecular forces occur between atoms in a molecule, while intermolecular forces occur between neighboring molecules. Intermolecular forces can be dipole-dipole forces, hydrogen bonding, or London dispersion forces.
Professor 1:
Water molecules represent an example of hydrogen bonding due to the attraction between the hydrogen atoms and the oxygen atoms in the molecule. This strong dipole-dipole occurs due to lone pairs present on such atoms as Fluorine, Nitrogen, and Oxygen, which are able to pair more closely to the hydrogen atom in another nearby molecule. Water can be present in a solid, liquid, or gaseous state on Earth depending on the competition between the strength of intermolecular bonds and the thermal energy of the system. In 1873, a Dutch scientist, Van der Waals derived an equation that included both the force of attraction between the particles of a gas and the volume of the particles at high pressures. This equation led to a better fit for experimental data than the Ideal Gas Law.
Professor 2:
Water is the only substance on Earth that we routinely encounter as a solid, liquid, and gas. At low temperatures, the water molecules lock into a rigid structure, but as the temperature increases, the average kinetic energy of the water molecules increases and the molecules are able to move more creating its other natural states of matter. The higher the temperature, the more likely water is to be a gas. Water is proof of the kinetic theory, which assumes that there is no force of attraction between the particles of the gas state. The best fit for experimental data involving water in a gaseous form is found by using the Ideal Gas Law, since there is no interaction between the gaseous molecules. This law accounts for all of the forces that occur with gases on Earth.
A 3rd professor mentions that he has he has seen Hydrogen Bonding have an effect on his experimental results. What would each professor say about his statement?
There are two types of forces that occur with all substances on Earth. Intramolecular forces occur between atoms in a molecule, while intermolecular forces occur between neighboring molecules. Intermolecular forces can be dipole-dipole forces, hydrogen bonding, or London dispersion forces.
Professor 1:
Water molecules represent an example of hydrogen bonding due to the attraction between the hydrogen atoms and the oxygen atoms in the molecule. This strong dipole-dipole occurs due to lone pairs present on such atoms as Fluorine, Nitrogen, and Oxygen, which are able to pair more closely to the hydrogen atom in another nearby molecule. Water can be present in a solid, liquid, or gaseous state on Earth depending on the competition between the strength of intermolecular bonds and the thermal energy of the system. In 1873, a Dutch scientist, Van der Waals derived an equation that included both the force of attraction between the particles of a gas and the volume of the particles at high pressures. This equation led to a better fit for experimental data than the Ideal Gas Law.
Professor 2:
Water is the only substance on Earth that we routinely encounter as a solid, liquid, and gas. At low temperatures, the water molecules lock into a rigid structure, but as the temperature increases, the average kinetic energy of the water molecules increases and the molecules are able to move more creating its other natural states of matter. The higher the temperature, the more likely water is to be a gas. Water is proof of the kinetic theory, which assumes that there is no force of attraction between the particles of the gas state. The best fit for experimental data involving water in a gaseous form is found by using the Ideal Gas Law, since there is no interaction between the gaseous molecules. This law accounts for all of the forces that occur with gases on Earth.
A 3rd professor mentions that he has he has seen Hydrogen Bonding have an effect on his experimental results. What would each professor say about his statement?
Professor 1 believes that use of the Van der Waals' equation is better than the Ideal Gas Law because it takes into effect the interaction between gas particles (such as Hydrogen Bonding). Professor 2 believes that there is no interaction between gas particles so the Ideal Gas Law is the best way to estimate experimental data.
Professor 1 believes that use of the Van der Waals' equation is better than the Ideal Gas Law because it takes into effect the interaction between gas particles (such as Hydrogen Bonding). Professor 2 believes that there is no interaction between gas particles so the Ideal Gas Law is the best way to estimate experimental data.
Compare your answer with the correct one above
In its refined form, iron is a shiny, silver-gray metal; however, when refined iron is exposed to atmospheric conditions for an extended period of time, its surface becomes flaky, pitted, and red- or orange-colored. This process is known as "rusting," and the new flaky, orange or red substance is called "rust."
Below, two scientists discuss how rust forms and the composition of rust.
Scientist 1:
Both water and oxygen are needed for rust to form. Water is an electrolyte_,_ meaning that it allows ions to move within it. When iron comes into contact with water, some iron naturally dissociates into iron ions (Fe2+) and free electrons. Additionally, when atmospheric oxygen (O2) dissolves in water, some oxygen reacts with water to form hydroxide ions (OH-). Because water allows ions to move freely, iron ions and hydroxide ions combine to form a new compound: iron hydroxide. However, iron hydroxide is not a stable compound. Over time, as water evaporates, it changes into a hydrated form of iron oxide. This is rust.
Salts can act as catalysts for rust formation, meaning that they speed up the rate at which rust forms. However, rust can form in pure water, in the absence of added salts.
Increasing the ambient temperature increases the rate of rust formation. Additionally, increasing the amount of iron's surface area that is exposed to water also increases the rate at which rust forms. However, because a layer of rust is porous to water and oxygen, water and oxygen will continue to cause the interior of a piece of iron to rust even after the iron's surface has been rusted.
Scientist 2:
Attack by acids causes rust to form. In water, acids ionize to create positively-charged hydronium (H+) ions and negatively-charged anions. Hydronium ions are electron-deficient; because of this, they attract electrons from iron. This creates iron ions (Fe2+), which are soluble in water. Once dissolved in water, iron ions react with dissolved atmospheric oxygen (O2) to create iron oxide, or rust.
Acids can come from a variety of sources. For example, when carbon dioxide in the atmosphere dissolves in water, carbonic acid (H2CO3) is created. Carbonic acid is the most common cause of rusting. However, other environmental sources of acids exist. Rainwater is normally slightly acidic because it has come into contact with molecules in the atmosphere, like sulfur dioxide and nitrogen oxides. These molecules also dissolve in water to form acids. Additionally, iron itself may contain impurities such as phosphorous and sulfur, which react with water to produce acids. Both acidic environments and impurities within iron itself create the conditions under which iron rusts.
Rusting can be prevented by painting the surface of iron, thus preventing it from coming into contact with water, oxygen, and acids. Iron can also be protected in a process called "galvanizing," which involves coating iron in a thin layer of zinc. Because zinc is more reactive than iron, it is corroded while the iron is protected.
Boiling water does not contain dissolved oxygen. Suppose that a new piece of iron is immersed in boiling water for an extended period of time. Afterwards, scientists observe that the iron has rusted. How would this affect the arguments of Scientist 1 and Scientist 2?
In its refined form, iron is a shiny, silver-gray metal; however, when refined iron is exposed to atmospheric conditions for an extended period of time, its surface becomes flaky, pitted, and red- or orange-colored. This process is known as "rusting," and the new flaky, orange or red substance is called "rust."
Below, two scientists discuss how rust forms and the composition of rust.
Scientist 1:
Both water and oxygen are needed for rust to form. Water is an electrolyte_,_ meaning that it allows ions to move within it. When iron comes into contact with water, some iron naturally dissociates into iron ions (Fe2+) and free electrons. Additionally, when atmospheric oxygen (O2) dissolves in water, some oxygen reacts with water to form hydroxide ions (OH-). Because water allows ions to move freely, iron ions and hydroxide ions combine to form a new compound: iron hydroxide. However, iron hydroxide is not a stable compound. Over time, as water evaporates, it changes into a hydrated form of iron oxide. This is rust.
Salts can act as catalysts for rust formation, meaning that they speed up the rate at which rust forms. However, rust can form in pure water, in the absence of added salts.
Increasing the ambient temperature increases the rate of rust formation. Additionally, increasing the amount of iron's surface area that is exposed to water also increases the rate at which rust forms. However, because a layer of rust is porous to water and oxygen, water and oxygen will continue to cause the interior of a piece of iron to rust even after the iron's surface has been rusted.
Scientist 2:
Attack by acids causes rust to form. In water, acids ionize to create positively-charged hydronium (H+) ions and negatively-charged anions. Hydronium ions are electron-deficient; because of this, they attract electrons from iron. This creates iron ions (Fe2+), which are soluble in water. Once dissolved in water, iron ions react with dissolved atmospheric oxygen (O2) to create iron oxide, or rust.
Acids can come from a variety of sources. For example, when carbon dioxide in the atmosphere dissolves in water, carbonic acid (H2CO3) is created. Carbonic acid is the most common cause of rusting. However, other environmental sources of acids exist. Rainwater is normally slightly acidic because it has come into contact with molecules in the atmosphere, like sulfur dioxide and nitrogen oxides. These molecules also dissolve in water to form acids. Additionally, iron itself may contain impurities such as phosphorous and sulfur, which react with water to produce acids. Both acidic environments and impurities within iron itself create the conditions under which iron rusts.
Rusting can be prevented by painting the surface of iron, thus preventing it from coming into contact with water, oxygen, and acids. Iron can also be protected in a process called "galvanizing," which involves coating iron in a thin layer of zinc. Because zinc is more reactive than iron, it is corroded while the iron is protected.
Boiling water does not contain dissolved oxygen. Suppose that a new piece of iron is immersed in boiling water for an extended period of time. Afterwards, scientists observe that the iron has rusted. How would this affect the arguments of Scientist 1 and Scientist 2?
The arguments of both Scientist 1 and Scientist 2 involve atmospheric oxygen diffusing into water. For both scientists, this is one of the necessary events leading up to the formation of rust. According to the question, however, boiling water does not contain dissolved oxygen. So, if iron still rusted in water that did not contain oxygen, this would imply that the explanations of both Scientist 1 and Scientist 2 are wrong or incomplete.
The arguments of both Scientist 1 and Scientist 2 involve atmospheric oxygen diffusing into water. For both scientists, this is one of the necessary events leading up to the formation of rust. According to the question, however, boiling water does not contain dissolved oxygen. So, if iron still rusted in water that did not contain oxygen, this would imply that the explanations of both Scientist 1 and Scientist 2 are wrong or incomplete.
Compare your answer with the correct one above
In its refined form, iron is a shiny, silver-gray metal; however, when refined iron is exposed to atmospheric conditions for an extended period of time, its surface becomes flaky, pitted, and red- or orange-colored. This process is known as "rusting," and the new flaky, orange or red substance is called "rust."
Below, two scientists discuss how rust forms and the composition of rust.
Scientist 1:
Both water and oxygen are needed for rust to form. Water is an electrolyte_,_ meaning that it allows ions to move within it. When iron comes into contact with water, some iron naturally dissociates into iron ions (Fe2+) and free electrons. Additionally, when atmospheric oxygen (O2) dissolves in water, some oxygen reacts with water to form hydroxide ions (OH-). Because water allows ions to move freely, iron ions and hydroxide ions combine to form a new compound: iron hydroxide. However, iron hydroxide is not a stable compound. Over time, as water evaporates, it changes into a hydrated form of iron oxide. This is rust.
Salts can act as catalysts for rust formation, meaning that they speed up the rate at which rust forms. However, rust can form in pure water, in the absence of added salts.
Increasing the ambient temperature increases the rate of rust formation. Additionally, increasing the amount of iron's surface area that is exposed to water also increases the rate at which rust forms. However, because a layer of rust is porous to water and oxygen, water and oxygen will continue to cause the interior of a piece of iron to rust even after the iron's surface has been rusted.
Scientist 2:
Attack by acids causes rust to form. In water, acids ionize to create positively-charged hydronium (H+) ions and negatively-charged anions. Hydronium ions are electron-deficient; because of this, they attract electrons from iron. This creates iron ions (Fe2+), which are soluble in water. Once dissolved in water, iron ions react with dissolved atmospheric oxygen (O2) to create iron oxide, or rust.
Acids can come from a variety of sources. For example, when carbon dioxide in the atmosphere dissolves in water, carbonic acid (H2CO3) is created. Carbonic acid is the most common cause of rusting. However, other environmental sources of acids exist. Rainwater is normally slightly acidic because it has come into contact with molecules in the atmosphere, like sulfur dioxide and nitrogen oxides. These molecules also dissolve in water to form acids. Additionally, iron itself may contain impurities such as phosphorous and sulfur, which react with water to produce acids. Both acidic environments and impurities within iron itself create the conditions under which iron rusts.
Rusting can be prevented by painting the surface of iron, thus preventing it from coming into contact with water, oxygen, and acids. Iron can also be protected in a process called "galvanizing," which involves coating iron in a thin layer of zinc. Because zinc is more reactive than iron, it is corroded while the iron is protected.
An iron nail is placed in a flask of water, which has been boiled to release any dissolved oxygen. The flask is attached to a vacuum pump which removes the air inside it. Then the flask is sealed. Assuming that the explanation of Scientist 1 is correct, which of the following results will be observed?
In its refined form, iron is a shiny, silver-gray metal; however, when refined iron is exposed to atmospheric conditions for an extended period of time, its surface becomes flaky, pitted, and red- or orange-colored. This process is known as "rusting," and the new flaky, orange or red substance is called "rust."
Below, two scientists discuss how rust forms and the composition of rust.
Scientist 1:
Both water and oxygen are needed for rust to form. Water is an electrolyte_,_ meaning that it allows ions to move within it. When iron comes into contact with water, some iron naturally dissociates into iron ions (Fe2+) and free electrons. Additionally, when atmospheric oxygen (O2) dissolves in water, some oxygen reacts with water to form hydroxide ions (OH-). Because water allows ions to move freely, iron ions and hydroxide ions combine to form a new compound: iron hydroxide. However, iron hydroxide is not a stable compound. Over time, as water evaporates, it changes into a hydrated form of iron oxide. This is rust.
Salts can act as catalysts for rust formation, meaning that they speed up the rate at which rust forms. However, rust can form in pure water, in the absence of added salts.
Increasing the ambient temperature increases the rate of rust formation. Additionally, increasing the amount of iron's surface area that is exposed to water also increases the rate at which rust forms. However, because a layer of rust is porous to water and oxygen, water and oxygen will continue to cause the interior of a piece of iron to rust even after the iron's surface has been rusted.
Scientist 2:
Attack by acids causes rust to form. In water, acids ionize to create positively-charged hydronium (H+) ions and negatively-charged anions. Hydronium ions are electron-deficient; because of this, they attract electrons from iron. This creates iron ions (Fe2+), which are soluble in water. Once dissolved in water, iron ions react with dissolved atmospheric oxygen (O2) to create iron oxide, or rust.
Acids can come from a variety of sources. For example, when carbon dioxide in the atmosphere dissolves in water, carbonic acid (H2CO3) is created. Carbonic acid is the most common cause of rusting. However, other environmental sources of acids exist. Rainwater is normally slightly acidic because it has come into contact with molecules in the atmosphere, like sulfur dioxide and nitrogen oxides. These molecules also dissolve in water to form acids. Additionally, iron itself may contain impurities such as phosphorous and sulfur, which react with water to produce acids. Both acidic environments and impurities within iron itself create the conditions under which iron rusts.
Rusting can be prevented by painting the surface of iron, thus preventing it from coming into contact with water, oxygen, and acids. Iron can also be protected in a process called "galvanizing," which involves coating iron in a thin layer of zinc. Because zinc is more reactive than iron, it is corroded while the iron is protected.
An iron nail is placed in a flask of water, which has been boiled to release any dissolved oxygen. The flask is attached to a vacuum pump which removes the air inside it. Then the flask is sealed. Assuming that the explanation of Scientist 1 is correct, which of the following results will be observed?
Scientist 1 states that for rust (hydrated iron oxide) to form, oxygen must dissolve in water and to react with water to form hydroxide ions. However, in this question, the vacuum pump removes all the air (including oxygen) in the flask. So, no oxygen would be able to react to produce hydroxide ions—meaning that no iron hydroxide will be produced, and no rust will be produced either.
Scientist 1 states that for rust (hydrated iron oxide) to form, oxygen must dissolve in water and to react with water to form hydroxide ions. However, in this question, the vacuum pump removes all the air (including oxygen) in the flask. So, no oxygen would be able to react to produce hydroxide ions—meaning that no iron hydroxide will be produced, and no rust will be produced either.
Compare your answer with the correct one above
In its refined form, iron is a shiny, silver-gray metal; however, when refined iron is exposed to atmospheric conditions for an extended period of time, its surface becomes flaky, pitted, and red- or orange-colored. This process is known as "rusting," and the new flaky, orange or red substance is called "rust."
Below, two scientists discuss how rust forms and the composition of rust.
Scientist 1:
Both water and oxygen are needed for rust to form. Water is an electrolyte_,_ meaning that it allows ions to move within it. When iron comes into contact with water, some iron naturally dissociates into iron ions (Fe2+) and free electrons. Additionally, when atmospheric oxygen (O2) dissolves in water, some oxygen reacts with water to form hydroxide ions (OH-). Because water allows ions to move freely, iron ions and hydroxide ions combine to form a new compound: iron hydroxide. However, iron hydroxide is not a stable compound. Over time, as water evaporates, it changes into a hydrated form of iron oxide. This is rust.
Salts can act as catalysts for rust formation, meaning that they speed up the rate at which rust forms. However, rust can form in pure water, in the absence of added salts.
Increasing the ambient temperature increases the rate of rust formation. Additionally, increasing the amount of iron's surface area that is exposed to water also increases the rate at which rust forms. However, because a layer of rust is porous to water and oxygen, water and oxygen will continue to cause the interior of a piece of iron to rust even after the iron's surface has been rusted.
Scientist 2:
Attack by acids causes rust to form. In water, acids ionize to create positively-charged hydronium (H+) ions and negatively-charged anions. Hydronium ions are electron-deficient; because of this, they attract electrons from iron. This creates iron ions (Fe2+), which are soluble in water. Once dissolved in water, iron ions react with dissolved atmospheric oxygen (O2) to create iron oxide, or rust.
Acids can come from a variety of sources. For example, when carbon dioxide in the atmosphere dissolves in water, carbonic acid (H2CO3) is created. Carbonic acid is the most common cause of rusting. However, other environmental sources of acids exist. Rainwater is normally slightly acidic because it has come into contact with molecules in the atmosphere, like sulfur dioxide and nitrogen oxides. These molecules also dissolve in water to form acids. Additionally, iron itself may contain impurities such as phosphorous and sulfur, which react with water to produce acids. Both acidic environments and impurities within iron itself create the conditions under which iron rusts.
Rusting can be prevented by painting the surface of iron, thus preventing it from coming into contact with water, oxygen, and acids. Iron can also be protected in a process called "galvanizing," which involves coating iron in a thin layer of zinc. Because zinc is more reactive than iron, it is corroded while the iron is protected.
An iron nail is placed in a test tube filled with water. Then, a layer of oil is poured over the water. After an extended period of time, no rust is observed to have formed on the iron nail. Scientist 1 would most likely explain this result by saying that:
In its refined form, iron is a shiny, silver-gray metal; however, when refined iron is exposed to atmospheric conditions for an extended period of time, its surface becomes flaky, pitted, and red- or orange-colored. This process is known as "rusting," and the new flaky, orange or red substance is called "rust."
Below, two scientists discuss how rust forms and the composition of rust.
Scientist 1:
Both water and oxygen are needed for rust to form. Water is an electrolyte_,_ meaning that it allows ions to move within it. When iron comes into contact with water, some iron naturally dissociates into iron ions (Fe2+) and free electrons. Additionally, when atmospheric oxygen (O2) dissolves in water, some oxygen reacts with water to form hydroxide ions (OH-). Because water allows ions to move freely, iron ions and hydroxide ions combine to form a new compound: iron hydroxide. However, iron hydroxide is not a stable compound. Over time, as water evaporates, it changes into a hydrated form of iron oxide. This is rust.
Salts can act as catalysts for rust formation, meaning that they speed up the rate at which rust forms. However, rust can form in pure water, in the absence of added salts.
Increasing the ambient temperature increases the rate of rust formation. Additionally, increasing the amount of iron's surface area that is exposed to water also increases the rate at which rust forms. However, because a layer of rust is porous to water and oxygen, water and oxygen will continue to cause the interior of a piece of iron to rust even after the iron's surface has been rusted.
Scientist 2:
Attack by acids causes rust to form. In water, acids ionize to create positively-charged hydronium (H+) ions and negatively-charged anions. Hydronium ions are electron-deficient; because of this, they attract electrons from iron. This creates iron ions (Fe2+), which are soluble in water. Once dissolved in water, iron ions react with dissolved atmospheric oxygen (O2) to create iron oxide, or rust.
Acids can come from a variety of sources. For example, when carbon dioxide in the atmosphere dissolves in water, carbonic acid (H2CO3) is created. Carbonic acid is the most common cause of rusting. However, other environmental sources of acids exist. Rainwater is normally slightly acidic because it has come into contact with molecules in the atmosphere, like sulfur dioxide and nitrogen oxides. These molecules also dissolve in water to form acids. Additionally, iron itself may contain impurities such as phosphorous and sulfur, which react with water to produce acids. Both acidic environments and impurities within iron itself create the conditions under which iron rusts.
Rusting can be prevented by painting the surface of iron, thus preventing it from coming into contact with water, oxygen, and acids. Iron can also be protected in a process called "galvanizing," which involves coating iron in a thin layer of zinc. Because zinc is more reactive than iron, it is corroded while the iron is protected.
An iron nail is placed in a test tube filled with water. Then, a layer of oil is poured over the water. After an extended period of time, no rust is observed to have formed on the iron nail. Scientist 1 would most likely explain this result by saying that:
Scientist 1 states that for rust to form, oxygen must dissolve in water and react with water to form hydroxide (OH-) ions. In this case, no rust is observed to form. This suggests that the layer of oil blocked the diffusion of oxygen into the water, preventing the production of OH- ions—and thus, of rust.
Scientist 1 states that for rust to form, oxygen must dissolve in water and react with water to form hydroxide (OH-) ions. In this case, no rust is observed to form. This suggests that the layer of oil blocked the diffusion of oxygen into the water, preventing the production of OH- ions—and thus, of rust.
Compare your answer with the correct one above
In its refined form, iron is a shiny, silver-gray metal; however, when refined iron is exposed to atmospheric conditions for an extended period of time, its surface becomes flaky, pitted, and red- or orange-colored. This process is known as "rusting," and the new flaky, orange or red substance is called "rust."
Below, two scientists discuss how rust forms and the composition of rust.
Scientist 1:
Both water and oxygen are needed for rust to form. Water is an electrolyte_,_ meaning that it allows ions to move within it. When iron comes into contact with water, some iron naturally dissociates into iron ions (Fe2+) and free electrons. Additionally, when atmospheric oxygen (O2) dissolves in water, some oxygen reacts with water to form hydroxide ions (OH-). Because water allows ions to move freely, iron ions and hydroxide ions combine to form a new compound: iron hydroxide. However, iron hydroxide is not a stable compound. Over time, as water evaporates, it changes into a hydrated form of iron oxide. This is rust.
Salts can act as catalysts for rust formation, meaning that they speed up the rate at which rust forms. However, rust can form in pure water, in the absence of added salts.
Increasing the ambient temperature increases the rate of rust formation. Additionally, increasing the amount of iron's surface area that is exposed to water also increases the rate at which rust forms. However, because a layer of rust is porous to water and oxygen, water and oxygen will continue to cause the interior of a piece of iron to rust even after the iron's surface has been rusted.
Scientist 2:
Attack by acids causes rust to form. In water, acids ionize to create positively-charged hydronium (H+) ions and negatively-charged anions. Hydronium ions are electron-deficient; because of this, they attract electrons from iron. This creates iron ions (Fe2+), which are soluble in water. Once dissolved in water, iron ions react with dissolved atmospheric oxygen (O2) to create iron oxide, or rust.
Acids can come from a variety of sources. For example, when carbon dioxide in the atmosphere dissolves in water, carbonic acid (H2CO3) is created. Carbonic acid is the most common cause of rusting. However, other environmental sources of acids exist. Rainwater is normally slightly acidic because it has come into contact with molecules in the atmosphere, like sulfur dioxide and nitrogen oxides. These molecules also dissolve in water to form acids. Additionally, iron itself may contain impurities such as phosphorous and sulfur, which react with water to produce acids. Both acidic environments and impurities within iron itself create the conditions under which iron rusts.
Rusting can be prevented by painting the surface of iron, thus preventing it from coming into contact with water, oxygen, and acids. Iron can also be protected in a process called "galvanizing," which involves coating iron in a thin layer of zinc. Because zinc is more reactive than iron, it is corroded while the iron is protected.
Given that all of the following are true, which of the following, if found, provides the strongest evidence against Scientist 1's hypothesis?
In its refined form, iron is a shiny, silver-gray metal; however, when refined iron is exposed to atmospheric conditions for an extended period of time, its surface becomes flaky, pitted, and red- or orange-colored. This process is known as "rusting," and the new flaky, orange or red substance is called "rust."
Below, two scientists discuss how rust forms and the composition of rust.
Scientist 1:
Both water and oxygen are needed for rust to form. Water is an electrolyte_,_ meaning that it allows ions to move within it. When iron comes into contact with water, some iron naturally dissociates into iron ions (Fe2+) and free electrons. Additionally, when atmospheric oxygen (O2) dissolves in water, some oxygen reacts with water to form hydroxide ions (OH-). Because water allows ions to move freely, iron ions and hydroxide ions combine to form a new compound: iron hydroxide. However, iron hydroxide is not a stable compound. Over time, as water evaporates, it changes into a hydrated form of iron oxide. This is rust.
Salts can act as catalysts for rust formation, meaning that they speed up the rate at which rust forms. However, rust can form in pure water, in the absence of added salts.
Increasing the ambient temperature increases the rate of rust formation. Additionally, increasing the amount of iron's surface area that is exposed to water also increases the rate at which rust forms. However, because a layer of rust is porous to water and oxygen, water and oxygen will continue to cause the interior of a piece of iron to rust even after the iron's surface has been rusted.
Scientist 2:
Attack by acids causes rust to form. In water, acids ionize to create positively-charged hydronium (H+) ions and negatively-charged anions. Hydronium ions are electron-deficient; because of this, they attract electrons from iron. This creates iron ions (Fe2+), which are soluble in water. Once dissolved in water, iron ions react with dissolved atmospheric oxygen (O2) to create iron oxide, or rust.
Acids can come from a variety of sources. For example, when carbon dioxide in the atmosphere dissolves in water, carbonic acid (H2CO3) is created. Carbonic acid is the most common cause of rusting. However, other environmental sources of acids exist. Rainwater is normally slightly acidic because it has come into contact with molecules in the atmosphere, like sulfur dioxide and nitrogen oxides. These molecules also dissolve in water to form acids. Additionally, iron itself may contain impurities such as phosphorous and sulfur, which react with water to produce acids. Both acidic environments and impurities within iron itself create the conditions under which iron rusts.
Rusting can be prevented by painting the surface of iron, thus preventing it from coming into contact with water, oxygen, and acids. Iron can also be protected in a process called "galvanizing," which involves coating iron in a thin layer of zinc. Because zinc is more reactive than iron, it is corroded while the iron is protected.
Given that all of the following are true, which of the following, if found, provides the strongest evidence against Scientist 1's hypothesis?
According to Scientist 1, the production of hydroxide ions is needed in order for rust to form. Scientist 1 states that hydroxide ions combine with soluble iron ions to form iron hydroxide, which then changes into hydrated iron oxide, or rust. Since hydroxide ions are one of the reactants used to produce rust, increasing the concentration of hydroxide ions in a solution should speed up the formation of rust. However, if increasing the hydroxide concentration actually slows down the formation of rust, this would suggest that Scientist 1's explanation is incorrect.
According to Scientist 1, the production of hydroxide ions is needed in order for rust to form. Scientist 1 states that hydroxide ions combine with soluble iron ions to form iron hydroxide, which then changes into hydrated iron oxide, or rust. Since hydroxide ions are one of the reactants used to produce rust, increasing the concentration of hydroxide ions in a solution should speed up the formation of rust. However, if increasing the hydroxide concentration actually slows down the formation of rust, this would suggest that Scientist 1's explanation is incorrect.
Compare your answer with the correct one above
In its refined form, iron is a shiny, silver-gray metal; however, when refined iron is exposed to atmospheric conditions for an extended period of time, its surface becomes flaky, pitted, and red- or orange-colored. This process is known as "rusting," and the new flaky, orange or red substance is called "rust."
Below, two scientists discuss how rust forms and the composition of rust.
Scientist 1:
Both water and oxygen are needed for rust to form. Water is an electrolyte_,_ meaning that it allows ions to move within it. When iron comes into contact with water, some iron naturally dissociates into iron ions (Fe2+) and free electrons. Additionally, when atmospheric oxygen (O2) dissolves in water, some oxygen reacts with water to form hydroxide ions (OH-). Because water allows ions to move freely, iron ions and hydroxide ions combine to form a new compound: iron hydroxide. However, iron hydroxide is not a stable compound. Over time, as water evaporates, it changes into a hydrated form of iron oxide. This is rust.
Salts can act as catalysts for rust formation, meaning that they speed up the rate at which rust forms. However, rust can form in pure water, in the absence of added salts.
Increasing the ambient temperature increases the rate of rust formation. Additionally, increasing the amount of iron's surface area that is exposed to water also increases the rate at which rust forms. However, because a layer of rust is porous to water and oxygen, water and oxygen will continue to cause the interior of a piece of iron to rust even after the iron's surface has been rusted.
Scientist 2:
Attack by acids causes rust to form. In water, acids ionize to create positively-charged hydronium (H+) ions and negatively-charged anions. Hydronium ions are electron-deficient; because of this, they attract electrons from iron. This creates iron ions (Fe2+), which are soluble in water. Once dissolved in water, iron ions react with dissolved atmospheric oxygen (O2) to create iron oxide, or rust.
Acids can come from a variety of sources. For example, when carbon dioxide in the atmosphere dissolves in water, carbonic acid (H2CO3) is created. Carbonic acid is the most common cause of rusting. However, other environmental sources of acids exist. Rainwater is normally slightly acidic because it has come into contact with molecules in the atmosphere, like sulfur dioxide and nitrogen oxides. These molecules also dissolve in water to form acids. Additionally, iron itself may contain impurities such as phosphorous and sulfur, which react with water to produce acids. Both acidic environments and impurities within iron itself create the conditions under which iron rusts.
Rusting can be prevented by painting the surface of iron, thus preventing it from coming into contact with water, oxygen, and acids. Iron can also be protected in a process called "galvanizing," which involves coating iron in a thin layer of zinc. Because zinc is more reactive than iron, it is corroded while the iron is protected.
Given that all of the following are true, which of the following, if found, provides the strongest evidence against Scientist 2's hypothesis?
In its refined form, iron is a shiny, silver-gray metal; however, when refined iron is exposed to atmospheric conditions for an extended period of time, its surface becomes flaky, pitted, and red- or orange-colored. This process is known as "rusting," and the new flaky, orange or red substance is called "rust."
Below, two scientists discuss how rust forms and the composition of rust.
Scientist 1:
Both water and oxygen are needed for rust to form. Water is an electrolyte_,_ meaning that it allows ions to move within it. When iron comes into contact with water, some iron naturally dissociates into iron ions (Fe2+) and free electrons. Additionally, when atmospheric oxygen (O2) dissolves in water, some oxygen reacts with water to form hydroxide ions (OH-). Because water allows ions to move freely, iron ions and hydroxide ions combine to form a new compound: iron hydroxide. However, iron hydroxide is not a stable compound. Over time, as water evaporates, it changes into a hydrated form of iron oxide. This is rust.
Salts can act as catalysts for rust formation, meaning that they speed up the rate at which rust forms. However, rust can form in pure water, in the absence of added salts.
Increasing the ambient temperature increases the rate of rust formation. Additionally, increasing the amount of iron's surface area that is exposed to water also increases the rate at which rust forms. However, because a layer of rust is porous to water and oxygen, water and oxygen will continue to cause the interior of a piece of iron to rust even after the iron's surface has been rusted.
Scientist 2:
Attack by acids causes rust to form. In water, acids ionize to create positively-charged hydronium (H+) ions and negatively-charged anions. Hydronium ions are electron-deficient; because of this, they attract electrons from iron. This creates iron ions (Fe2+), which are soluble in water. Once dissolved in water, iron ions react with dissolved atmospheric oxygen (O2) to create iron oxide, or rust.
Acids can come from a variety of sources. For example, when carbon dioxide in the atmosphere dissolves in water, carbonic acid (H2CO3) is created. Carbonic acid is the most common cause of rusting. However, other environmental sources of acids exist. Rainwater is normally slightly acidic because it has come into contact with molecules in the atmosphere, like sulfur dioxide and nitrogen oxides. These molecules also dissolve in water to form acids. Additionally, iron itself may contain impurities such as phosphorous and sulfur, which react with water to produce acids. Both acidic environments and impurities within iron itself create the conditions under which iron rusts.
Rusting can be prevented by painting the surface of iron, thus preventing it from coming into contact with water, oxygen, and acids. Iron can also be protected in a process called "galvanizing," which involves coating iron in a thin layer of zinc. Because zinc is more reactive than iron, it is corroded while the iron is protected.
Given that all of the following are true, which of the following, if found, provides the strongest evidence against Scientist 2's hypothesis?
Scientist 2 states that acid is required for rust to form. Because acid releases H+ ions—which, according to Scientist 2, are involved in the production of rust—we should expect that adding more acid to a solution will speed up the formation of rust. If, however, adding citric acid actually reverses rusting or removes rust (causing a piece of iron to become shiny again), this would suggest that Scientist 2's explanation is wrong.
Scientist 2 also states that acid may be formed in a solution because of atmospheric carbon dioxide dissolving in the water or because of impurities in a piece of iron. So, rust may form even when no acid is directly added to water. It is also possible that different amounts of impurities in different pieces of iron cause them to rust at different rates. This is why some of the other answers are not correct.
Scientist 2 states that acid is required for rust to form. Because acid releases H+ ions—which, according to Scientist 2, are involved in the production of rust—we should expect that adding more acid to a solution will speed up the formation of rust. If, however, adding citric acid actually reverses rusting or removes rust (causing a piece of iron to become shiny again), this would suggest that Scientist 2's explanation is wrong.
Scientist 2 also states that acid may be formed in a solution because of atmospheric carbon dioxide dissolving in the water or because of impurities in a piece of iron. So, rust may form even when no acid is directly added to water. It is also possible that different amounts of impurities in different pieces of iron cause them to rust at different rates. This is why some of the other answers are not correct.
Compare your answer with the correct one above
In its refined form, iron is a shiny, silver-gray metal; however, when refined iron is exposed to atmospheric conditions for an extended period of time, its surface becomes flaky, pitted, and red- or orange-colored. This process is known as "rusting," and the new flaky, orange or red substance is called "rust."
Below, two scientists discuss how rust forms and the composition of rust.
Scientist 1:
Both water and oxygen are needed for rust to form. Water is an electrolyte_,_ meaning that it allows ions to move within it. When iron comes into contact with water, some iron naturally dissociates into iron ions (Fe2+) and free electrons. Additionally, when atmospheric oxygen (O2) dissolves in water, some oxygen reacts with water to form hydroxide ions (OH-). Because water allows ions to move freely, iron ions and hydroxide ions combine to form a new compound: iron hydroxide. However, iron hydroxide is not a stable compound. Over time, as water evaporates, it changes into a hydrated form of iron oxide. This is rust.
Salts can act as catalysts for rust formation, meaning that they speed up the rate at which rust forms. However, rust can form in pure water, in the absence of added salts.
Increasing the ambient temperature increases the rate of rust formation. Additionally, increasing the amount of iron's surface area that is exposed to water also increases the rate at which rust forms. However, because a layer of rust is porous to water and oxygen, water and oxygen will continue to cause the interior of a piece of iron to rust even after the iron's surface has been rusted.
Scientist 2:
Attack by acids causes rust to form. In water, acids ionize to create positively-charged hydronium (H+) ions and negatively-charged anions. Hydronium ions are electron-deficient; because of this, they attract electrons from iron. This creates iron ions (Fe2+), which are soluble in water. Once dissolved in water, iron ions react with dissolved atmospheric oxygen (O2) to create iron oxide, or rust.
Acids can come from a variety of sources. For example, when carbon dioxide in the atmosphere dissolves in water, carbonic acid (H2CO3) is created. Carbonic acid is the most common cause of rusting. However, other environmental sources of acids exist. Rainwater is normally slightly acidic because it has come into contact with molecules in the atmosphere, like sulfur dioxide and nitrogen oxides. These molecules also dissolve in water to form acids. Additionally, iron itself may contain impurities such as phosphorous and sulfur, which react with water to produce acids. Both acidic environments and impurities within iron itself create the conditions under which iron rusts.
Rusting can be prevented by painting the surface of iron, thus preventing it from coming into contact with water, oxygen, and acids. Iron can also be protected in a process called "galvanizing," which involves coating iron in a thin layer of zinc. Because zinc is more reactive than iron, it is corroded while the iron is protected.
Lye (sodium hydroxide) is a base that neutralizes acids. Suppose that lye is added to water in which an iron pipe has been immersed. According to Scientist 2, the pipe's rate of rusting will most likely __________.
In its refined form, iron is a shiny, silver-gray metal; however, when refined iron is exposed to atmospheric conditions for an extended period of time, its surface becomes flaky, pitted, and red- or orange-colored. This process is known as "rusting," and the new flaky, orange or red substance is called "rust."
Below, two scientists discuss how rust forms and the composition of rust.
Scientist 1:
Both water and oxygen are needed for rust to form. Water is an electrolyte_,_ meaning that it allows ions to move within it. When iron comes into contact with water, some iron naturally dissociates into iron ions (Fe2+) and free electrons. Additionally, when atmospheric oxygen (O2) dissolves in water, some oxygen reacts with water to form hydroxide ions (OH-). Because water allows ions to move freely, iron ions and hydroxide ions combine to form a new compound: iron hydroxide. However, iron hydroxide is not a stable compound. Over time, as water evaporates, it changes into a hydrated form of iron oxide. This is rust.
Salts can act as catalysts for rust formation, meaning that they speed up the rate at which rust forms. However, rust can form in pure water, in the absence of added salts.
Increasing the ambient temperature increases the rate of rust formation. Additionally, increasing the amount of iron's surface area that is exposed to water also increases the rate at which rust forms. However, because a layer of rust is porous to water and oxygen, water and oxygen will continue to cause the interior of a piece of iron to rust even after the iron's surface has been rusted.
Scientist 2:
Attack by acids causes rust to form. In water, acids ionize to create positively-charged hydronium (H+) ions and negatively-charged anions. Hydronium ions are electron-deficient; because of this, they attract electrons from iron. This creates iron ions (Fe2+), which are soluble in water. Once dissolved in water, iron ions react with dissolved atmospheric oxygen (O2) to create iron oxide, or rust.
Acids can come from a variety of sources. For example, when carbon dioxide in the atmosphere dissolves in water, carbonic acid (H2CO3) is created. Carbonic acid is the most common cause of rusting. However, other environmental sources of acids exist. Rainwater is normally slightly acidic because it has come into contact with molecules in the atmosphere, like sulfur dioxide and nitrogen oxides. These molecules also dissolve in water to form acids. Additionally, iron itself may contain impurities such as phosphorous and sulfur, which react with water to produce acids. Both acidic environments and impurities within iron itself create the conditions under which iron rusts.
Rusting can be prevented by painting the surface of iron, thus preventing it from coming into contact with water, oxygen, and acids. Iron can also be protected in a process called "galvanizing," which involves coating iron in a thin layer of zinc. Because zinc is more reactive than iron, it is corroded while the iron is protected.
Lye (sodium hydroxide) is a base that neutralizes acids. Suppose that lye is added to water in which an iron pipe has been immersed. According to Scientist 2, the pipe's rate of rusting will most likely __________.
According to Scientist 2, acid is needed for rust to form. However, the question tells us that lye neutralizes acids. So, if lye is added to the solution, the solution will become less acidic, and rust will not form, or form at a slower rate.
According to Scientist 2, acid is needed for rust to form. However, the question tells us that lye neutralizes acids. So, if lye is added to the solution, the solution will become less acidic, and rust will not form, or form at a slower rate.
Compare your answer with the correct one above
In its refined form, iron is a shiny, silver-gray metal; however, when refined iron is exposed to atmospheric conditions for an extended period of time, its surface becomes flaky, pitted, and red- or orange-colored. This process is known as "rusting," and the new flaky, orange or red substance is called "rust."
Below, two scientists discuss how rust forms and the composition of rust.
Scientist 1:
Both water and oxygen are needed for rust to form. Water is an electrolyte_,_ meaning that it allows ions to move within it. When iron comes into contact with water, some iron naturally dissociates into iron ions (Fe2+) and free electrons. Additionally, when atmospheric oxygen (O2) dissolves in water, some oxygen reacts with water to form hydroxide ions (OH-). Because water allows ions to move freely, iron ions and hydroxide ions combine to form a new compound: iron hydroxide. However, iron hydroxide is not a stable compound. Over time, as water evaporates, it changes into a hydrated form of iron oxide. This is rust.
Salts can act as catalysts for rust formation, meaning that they speed up the rate at which rust forms. However, rust can form in pure water, in the absence of added salts.
Increasing the ambient temperature increases the rate of rust formation. Additionally, increasing the amount of iron's surface area that is exposed to water also increases the rate at which rust forms. However, because a layer of rust is porous to water and oxygen, water and oxygen will continue to cause the interior of a piece of iron to rust even after the iron's surface has been rusted.
Scientist 2:
Attack by acids causes rust to form. In water, acids ionize to create positively-charged hydronium (H+) ions and negatively-charged anions. Hydronium ions are electron-deficient; because of this, they attract electrons from iron. This creates iron ions (Fe2+), which are soluble in water. Once dissolved in water, iron ions react with dissolved atmospheric oxygen (O2) to create iron oxide, or rust.
Acids can come from a variety of sources. For example, when carbon dioxide in the atmosphere dissolves in water, carbonic acid (H2CO3) is created. Carbonic acid is the most common cause of rusting. However, other environmental sources of acids exist. Rainwater is normally slightly acidic because it has come into contact with molecules in the atmosphere, like sulfur dioxide and nitrogen oxides. These molecules also dissolve in water to form acids. Additionally, iron itself may contain impurities such as phosphorous and sulfur, which react with water to produce acids. Both acidic environments and impurities within iron itself create the conditions under which iron rusts.
Rusting can be prevented by painting the surface of iron, thus preventing it from coming into contact with water, oxygen, and acids. Iron can also be protected in a process called "galvanizing," which involves coating iron in a thin layer of zinc. Because zinc is more reactive than iron, it is corroded while the iron is protected.
An iron nail is placed in an unsealed test tube filled with water. No other substances are added to the water. When the nail is removed after an extended period of time, it is covered by rust. According the Scientist 2, the nail most likely rusted because __________.
In its refined form, iron is a shiny, silver-gray metal; however, when refined iron is exposed to atmospheric conditions for an extended period of time, its surface becomes flaky, pitted, and red- or orange-colored. This process is known as "rusting," and the new flaky, orange or red substance is called "rust."
Below, two scientists discuss how rust forms and the composition of rust.
Scientist 1:
Both water and oxygen are needed for rust to form. Water is an electrolyte_,_ meaning that it allows ions to move within it. When iron comes into contact with water, some iron naturally dissociates into iron ions (Fe2+) and free electrons. Additionally, when atmospheric oxygen (O2) dissolves in water, some oxygen reacts with water to form hydroxide ions (OH-). Because water allows ions to move freely, iron ions and hydroxide ions combine to form a new compound: iron hydroxide. However, iron hydroxide is not a stable compound. Over time, as water evaporates, it changes into a hydrated form of iron oxide. This is rust.
Salts can act as catalysts for rust formation, meaning that they speed up the rate at which rust forms. However, rust can form in pure water, in the absence of added salts.
Increasing the ambient temperature increases the rate of rust formation. Additionally, increasing the amount of iron's surface area that is exposed to water also increases the rate at which rust forms. However, because a layer of rust is porous to water and oxygen, water and oxygen will continue to cause the interior of a piece of iron to rust even after the iron's surface has been rusted.
Scientist 2:
Attack by acids causes rust to form. In water, acids ionize to create positively-charged hydronium (H+) ions and negatively-charged anions. Hydronium ions are electron-deficient; because of this, they attract electrons from iron. This creates iron ions (Fe2+), which are soluble in water. Once dissolved in water, iron ions react with dissolved atmospheric oxygen (O2) to create iron oxide, or rust.
Acids can come from a variety of sources. For example, when carbon dioxide in the atmosphere dissolves in water, carbonic acid (H2CO3) is created. Carbonic acid is the most common cause of rusting. However, other environmental sources of acids exist. Rainwater is normally slightly acidic because it has come into contact with molecules in the atmosphere, like sulfur dioxide and nitrogen oxides. These molecules also dissolve in water to form acids. Additionally, iron itself may contain impurities such as phosphorous and sulfur, which react with water to produce acids. Both acidic environments and impurities within iron itself create the conditions under which iron rusts.
Rusting can be prevented by painting the surface of iron, thus preventing it from coming into contact with water, oxygen, and acids. Iron can also be protected in a process called "galvanizing," which involves coating iron in a thin layer of zinc. Because zinc is more reactive than iron, it is corroded while the iron is protected.
An iron nail is placed in an unsealed test tube filled with water. No other substances are added to the water. When the nail is removed after an extended period of time, it is covered by rust. According the Scientist 2, the nail most likely rusted because __________.
According to Scientist 2, acid is needed for rust to form. However, Scientist 2 also tells us that acid may form spontaneously when carbon dioxide from the air dissolves in water and reacts to form carbonic acid. In this experiment, because it was observed that the iron nail did rust, some acid must have been in the water. This acid might have been carbonic acid produced from carbon dioxide, or other acids produced from impurities contained in the iron nail. Out of these two options, the only one listed as a possible answer choice is the situation involving carbon dioxide and carbonic acid.
According to Scientist 2, acid is needed for rust to form. However, Scientist 2 also tells us that acid may form spontaneously when carbon dioxide from the air dissolves in water and reacts to form carbonic acid. In this experiment, because it was observed that the iron nail did rust, some acid must have been in the water. This acid might have been carbonic acid produced from carbon dioxide, or other acids produced from impurities contained in the iron nail. Out of these two options, the only one listed as a possible answer choice is the situation involving carbon dioxide and carbonic acid.
Compare your answer with the correct one above
In its refined form, iron is a shiny, silver-gray metal; however, when refined iron is exposed to atmospheric conditions for an extended period of time, its surface becomes flaky, pitted, and red- or orange-colored. This process is known as "rusting," and the new flaky, orange or red substance is called "rust."
Below, two scientists discuss how rust forms and the composition of rust.
Scientist 1:
Both water and oxygen are needed for rust to form. Water is an electrolyte_,_ meaning that it allows ions to move within it. When iron comes into contact with water, some iron naturally dissociates into iron ions (Fe2+) and free electrons. Additionally, when atmospheric oxygen (O2) dissolves in water, some oxygen reacts with water to form hydroxide ions (OH-). Because water allows ions to move freely, iron ions and hydroxide ions combine to form a new compound: iron hydroxide. However, iron hydroxide is not a stable compound. Over time, as water evaporates, it changes into a hydrated form of iron oxide. This is rust.
Salts can act as catalysts for rust formation, meaning that they speed up the rate at which rust forms. However, rust can form in pure water, in the absence of added salts.
Increasing the ambient temperature increases the rate of rust formation. Additionally, increasing the amount of iron's surface area that is exposed to water also increases the rate at which rust forms. However, because a layer of rust is porous to water and oxygen, water and oxygen will continue to cause the interior of a piece of iron to rust even after the iron's surface has been rusted.
Scientist 2:
Attack by acids causes rust to form. In water, acids ionize to create positively-charged hydronium (H+) ions and negatively-charged anions. Hydronium ions are electron-deficient; because of this, they attract electrons from iron. This creates iron ions (Fe2+), which are soluble in water. Once dissolved in water, iron ions react with dissolved atmospheric oxygen (O2) to create iron oxide, or rust.
Acids can come from a variety of sources. For example, when carbon dioxide in the atmosphere dissolves in water, carbonic acid (H2CO3) is created. Carbonic acid is the most common cause of rusting. However, other environmental sources of acids exist. Rainwater is normally slightly acidic because it has come into contact with molecules in the atmosphere, like sulfur dioxide and nitrogen oxides. These molecules also dissolve in water to form acids. Additionally, iron itself may contain impurities such as phosphorous and sulfur, which react with water to produce acids. Both acidic environments and impurities within iron itself create the conditions under which iron rusts.
Rusting can be prevented by painting the surface of iron, thus preventing it from coming into contact with water, oxygen, and acids. Iron can also be protected in a process called "galvanizing," which involves coating iron in a thin layer of zinc. Because zinc is more reactive than iron, it is corroded while the iron is protected.
Sodium hydroxide (NaOH) is a compound which dissociates into Na+ and OH- ions in solution. Suppose that sodium hydroxide is added to water in which a piece of iron has been immersed. It is then observed that the rate at which rust forms on the iron increases. Scientist 1 would most likely explain this result by saying that __________.
In its refined form, iron is a shiny, silver-gray metal; however, when refined iron is exposed to atmospheric conditions for an extended period of time, its surface becomes flaky, pitted, and red- or orange-colored. This process is known as "rusting," and the new flaky, orange or red substance is called "rust."
Below, two scientists discuss how rust forms and the composition of rust.
Scientist 1:
Both water and oxygen are needed for rust to form. Water is an electrolyte_,_ meaning that it allows ions to move within it. When iron comes into contact with water, some iron naturally dissociates into iron ions (Fe2+) and free electrons. Additionally, when atmospheric oxygen (O2) dissolves in water, some oxygen reacts with water to form hydroxide ions (OH-). Because water allows ions to move freely, iron ions and hydroxide ions combine to form a new compound: iron hydroxide. However, iron hydroxide is not a stable compound. Over time, as water evaporates, it changes into a hydrated form of iron oxide. This is rust.
Salts can act as catalysts for rust formation, meaning that they speed up the rate at which rust forms. However, rust can form in pure water, in the absence of added salts.
Increasing the ambient temperature increases the rate of rust formation. Additionally, increasing the amount of iron's surface area that is exposed to water also increases the rate at which rust forms. However, because a layer of rust is porous to water and oxygen, water and oxygen will continue to cause the interior of a piece of iron to rust even after the iron's surface has been rusted.
Scientist 2:
Attack by acids causes rust to form. In water, acids ionize to create positively-charged hydronium (H+) ions and negatively-charged anions. Hydronium ions are electron-deficient; because of this, they attract electrons from iron. This creates iron ions (Fe2+), which are soluble in water. Once dissolved in water, iron ions react with dissolved atmospheric oxygen (O2) to create iron oxide, or rust.
Acids can come from a variety of sources. For example, when carbon dioxide in the atmosphere dissolves in water, carbonic acid (H2CO3) is created. Carbonic acid is the most common cause of rusting. However, other environmental sources of acids exist. Rainwater is normally slightly acidic because it has come into contact with molecules in the atmosphere, like sulfur dioxide and nitrogen oxides. These molecules also dissolve in water to form acids. Additionally, iron itself may contain impurities such as phosphorous and sulfur, which react with water to produce acids. Both acidic environments and impurities within iron itself create the conditions under which iron rusts.
Rusting can be prevented by painting the surface of iron, thus preventing it from coming into contact with water, oxygen, and acids. Iron can also be protected in a process called "galvanizing," which involves coating iron in a thin layer of zinc. Because zinc is more reactive than iron, it is corroded while the iron is protected.
Sodium hydroxide (NaOH) is a compound which dissociates into Na+ and OH- ions in solution. Suppose that sodium hydroxide is added to water in which a piece of iron has been immersed. It is then observed that the rate at which rust forms on the iron increases. Scientist 1 would most likely explain this result by saying that __________.
According to Scientist 1, hydroxide (OH-) ions are one of the precursors involved in the formation of rust. Since sodium hydroxide dissociates into Na+ and OH- ions, adding sodium hydroxide to a solution would increase the concentration of OH- ions. If Scientist 1 is right, this should also speed up or facilitate the formation of iron hydroxide, which should then turn into rust.
According to Scientist 1, hydroxide (OH-) ions are one of the precursors involved in the formation of rust. Since sodium hydroxide dissociates into Na+ and OH- ions, adding sodium hydroxide to a solution would increase the concentration of OH- ions. If Scientist 1 is right, this should also speed up or facilitate the formation of iron hydroxide, which should then turn into rust.
Compare your answer with the correct one above
In its refined form, iron is a shiny, silver-gray metal; however, when refined iron is exposed to atmospheric conditions for an extended period of time, its surface becomes flaky, pitted, and red- or orange-colored. This process is known as "rusting," and the new flaky, orange or red substance is called "rust."
Below, two scientists discuss how rust forms and the composition of rust.
Scientist 1:
Both water and oxygen are needed for rust to form. Water is an electrolyte_,_ meaning that it allows ions to move within it. When iron comes into contact with water, some iron naturally dissociates into iron ions (Fe2+) and free electrons. Additionally, when atmospheric oxygen (O2) dissolves in water, some oxygen reacts with water to form hydroxide ions (OH-). Because water allows ions to move freely, iron ions and hydroxide ions combine to form a new compound: iron hydroxide. However, iron hydroxide is not a stable compound. Over time, as water evaporates, it changes into a hydrated form of iron oxide. This is rust.
Salts can act as catalysts for rust formation, meaning that they speed up the rate at which rust forms. However, rust can form in pure water, in the absence of added salts.
Increasing the ambient temperature increases the rate of rust formation. Additionally, increasing the amount of iron's surface area that is exposed to water also increases the rate at which rust forms. However, because a layer of rust is porous to water and oxygen, water and oxygen will continue to cause the interior of a piece of iron to rust even after the iron's surface has been rusted.
Scientist 2:
Attack by acids causes rust to form. In water, acids ionize to create positively-charged hydronium (H+) ions and negatively-charged anions. Hydronium ions are electron-deficient; because of this, they attract electrons from iron. This creates iron ions (Fe2+), which are soluble in water. Once dissolved in water, iron ions react with dissolved atmospheric oxygen (O2) to create iron oxide, or rust.
Acids can come from a variety of sources. For example, when carbon dioxide in the atmosphere dissolves in water, carbonic acid (H2CO3) is created. Carbonic acid is the most common cause of rusting. However, other environmental sources of acids exist. Rainwater is normally slightly acidic because it has come into contact with molecules in the atmosphere, like sulfur dioxide and nitrogen oxides. These molecules also dissolve in water to form acids. Additionally, iron itself may contain impurities such as phosphorous and sulfur, which react with water to produce acids. Both acidic environments and impurities within iron itself create the conditions under which iron rusts.
Rusting can be prevented by painting the surface of iron, thus preventing it from coming into contact with water, oxygen, and acids. Iron can also be protected in a process called "galvanizing," which involves coating iron in a thin layer of zinc. Because zinc is more reactive than iron, it is corroded while the iron is protected.
According to Scientist 1, which of the following conditions will result in the least rapid formation of rust?
In its refined form, iron is a shiny, silver-gray metal; however, when refined iron is exposed to atmospheric conditions for an extended period of time, its surface becomes flaky, pitted, and red- or orange-colored. This process is known as "rusting," and the new flaky, orange or red substance is called "rust."
Below, two scientists discuss how rust forms and the composition of rust.
Scientist 1:
Both water and oxygen are needed for rust to form. Water is an electrolyte_,_ meaning that it allows ions to move within it. When iron comes into contact with water, some iron naturally dissociates into iron ions (Fe2+) and free electrons. Additionally, when atmospheric oxygen (O2) dissolves in water, some oxygen reacts with water to form hydroxide ions (OH-). Because water allows ions to move freely, iron ions and hydroxide ions combine to form a new compound: iron hydroxide. However, iron hydroxide is not a stable compound. Over time, as water evaporates, it changes into a hydrated form of iron oxide. This is rust.
Salts can act as catalysts for rust formation, meaning that they speed up the rate at which rust forms. However, rust can form in pure water, in the absence of added salts.
Increasing the ambient temperature increases the rate of rust formation. Additionally, increasing the amount of iron's surface area that is exposed to water also increases the rate at which rust forms. However, because a layer of rust is porous to water and oxygen, water and oxygen will continue to cause the interior of a piece of iron to rust even after the iron's surface has been rusted.
Scientist 2:
Attack by acids causes rust to form. In water, acids ionize to create positively-charged hydronium (H+) ions and negatively-charged anions. Hydronium ions are electron-deficient; because of this, they attract electrons from iron. This creates iron ions (Fe2+), which are soluble in water. Once dissolved in water, iron ions react with dissolved atmospheric oxygen (O2) to create iron oxide, or rust.
Acids can come from a variety of sources. For example, when carbon dioxide in the atmosphere dissolves in water, carbonic acid (H2CO3) is created. Carbonic acid is the most common cause of rusting. However, other environmental sources of acids exist. Rainwater is normally slightly acidic because it has come into contact with molecules in the atmosphere, like sulfur dioxide and nitrogen oxides. These molecules also dissolve in water to form acids. Additionally, iron itself may contain impurities such as phosphorous and sulfur, which react with water to produce acids. Both acidic environments and impurities within iron itself create the conditions under which iron rusts.
Rusting can be prevented by painting the surface of iron, thus preventing it from coming into contact with water, oxygen, and acids. Iron can also be protected in a process called "galvanizing," which involves coating iron in a thin layer of zinc. Because zinc is more reactive than iron, it is corroded while the iron is protected.
According to Scientist 1, which of the following conditions will result in the least rapid formation of rust?
Scientist 1 states that increasing the surface area of iron and increasing the ambient temperature both speed up the formation of rust. Additionally, she says that salt acts as a catalyst for rust formation, meaning that adding salt to a solution also speeds up the formation of rust. Because this question asks us for the situation under which rust will form least rapidly, the correct answer is the one in which iron has a smaller surface area (the iron strip) and is placed in cooler (5°C)water.
Scientist 1 states that increasing the surface area of iron and increasing the ambient temperature both speed up the formation of rust. Additionally, she says that salt acts as a catalyst for rust formation, meaning that adding salt to a solution also speeds up the formation of rust. Because this question asks us for the situation under which rust will form least rapidly, the correct answer is the one in which iron has a smaller surface area (the iron strip) and is placed in cooler (5°C)water.
Compare your answer with the correct one above
In its refined form, iron is a shiny, silver-gray metal; however, when refined iron is exposed to atmospheric conditions for an extended period of time, its surface becomes flaky, pitted, and red- or orange-colored. This process is known as "rusting," and the new flaky, orange or red substance is called "rust."
Below, two scientists discuss how rust forms and the composition of rust.
Scientist 1:
Both water and oxygen are needed for rust to form. Water is an electrolyte_,_ meaning that it allows ions to move within it. When iron comes into contact with water, some iron naturally dissociates into iron ions (Fe2+) and free electrons. Additionally, when atmospheric oxygen (O2) dissolves in water, some oxygen reacts with water to form hydroxide ions (OH-). Because water allows ions to move freely, iron ions and hydroxide ions combine to form a new compound: iron hydroxide. However, iron hydroxide is not a stable compound. Over time, as water evaporates, it changes into a hydrated form of iron oxide. This is rust.
Salts can act as catalysts for rust formation, meaning that they speed up the rate at which rust forms. However, rust can form in pure water, in the absence of added salts.
Increasing the ambient temperature increases the rate of rust formation. Additionally, increasing the amount of iron's surface area that is exposed to water also increases the rate at which rust forms. However, because a layer of rust is porous to water and oxygen, water and oxygen will continue to cause the interior of a piece of iron to rust even after the iron's surface has been rusted.
Scientist 2:
Attack by acids causes rust to form. In water, acids ionize to create positively-charged hydronium (H+) ions and negatively-charged anions. Hydronium ions are electron-deficient; because of this, they attract electrons from iron. This creates iron ions (Fe2+), which are soluble in water. Once dissolved in water, iron ions react with dissolved atmospheric oxygen (O2) to create iron oxide, or rust.
Acids can come from a variety of sources. For example, when carbon dioxide in the atmosphere dissolves in water, carbonic acid (H2CO3) is created. Carbonic acid is the most common cause of rusting. However, other environmental sources of acids exist. Rainwater is normally slightly acidic because it has come into contact with molecules in the atmosphere, like sulfur dioxide and nitrogen oxides. These molecules also dissolve in water to form acids. Additionally, iron itself may contain impurities such as phosphorous and sulfur, which react with water to produce acids. Both acidic environments and impurities within iron itself create the conditions under which iron rusts.
Rusting can be prevented by painting the surface of iron, thus preventing it from coming into contact with water, oxygen, and acids. Iron can also be protected in a process called "galvanizing," which involves coating iron in a thin layer of zinc. Because zinc is more reactive than iron, it is corroded while the iron is protected.
Given that the explanation of Scientist 2 is correct, which of the following conditions, if any, will result in the formation of rust?
In its refined form, iron is a shiny, silver-gray metal; however, when refined iron is exposed to atmospheric conditions for an extended period of time, its surface becomes flaky, pitted, and red- or orange-colored. This process is known as "rusting," and the new flaky, orange or red substance is called "rust."
Below, two scientists discuss how rust forms and the composition of rust.
Scientist 1:
Both water and oxygen are needed for rust to form. Water is an electrolyte_,_ meaning that it allows ions to move within it. When iron comes into contact with water, some iron naturally dissociates into iron ions (Fe2+) and free electrons. Additionally, when atmospheric oxygen (O2) dissolves in water, some oxygen reacts with water to form hydroxide ions (OH-). Because water allows ions to move freely, iron ions and hydroxide ions combine to form a new compound: iron hydroxide. However, iron hydroxide is not a stable compound. Over time, as water evaporates, it changes into a hydrated form of iron oxide. This is rust.
Salts can act as catalysts for rust formation, meaning that they speed up the rate at which rust forms. However, rust can form in pure water, in the absence of added salts.
Increasing the ambient temperature increases the rate of rust formation. Additionally, increasing the amount of iron's surface area that is exposed to water also increases the rate at which rust forms. However, because a layer of rust is porous to water and oxygen, water and oxygen will continue to cause the interior of a piece of iron to rust even after the iron's surface has been rusted.
Scientist 2:
Attack by acids causes rust to form. In water, acids ionize to create positively-charged hydronium (H+) ions and negatively-charged anions. Hydronium ions are electron-deficient; because of this, they attract electrons from iron. This creates iron ions (Fe2+), which are soluble in water. Once dissolved in water, iron ions react with dissolved atmospheric oxygen (O2) to create iron oxide, or rust.
Acids can come from a variety of sources. For example, when carbon dioxide in the atmosphere dissolves in water, carbonic acid (H2CO3) is created. Carbonic acid is the most common cause of rusting. However, other environmental sources of acids exist. Rainwater is normally slightly acidic because it has come into contact with molecules in the atmosphere, like sulfur dioxide and nitrogen oxides. These molecules also dissolve in water to form acids. Additionally, iron itself may contain impurities such as phosphorous and sulfur, which react with water to produce acids. Both acidic environments and impurities within iron itself create the conditions under which iron rusts.
Rusting can be prevented by painting the surface of iron, thus preventing it from coming into contact with water, oxygen, and acids. Iron can also be protected in a process called "galvanizing," which involves coating iron in a thin layer of zinc. Because zinc is more reactive than iron, it is corroded while the iron is protected.
Given that the explanation of Scientist 2 is correct, which of the following conditions, if any, will result in the formation of rust?
According to Scientist 2, water must contain oxygen and acid in order for rust to form. However, Scientist 2 says that even when no acid is directly added to water, carbon dioxide from the air can react with water to form carbonic acid. Oxygen can also dissolve from the air into the water. So, if an iron pot is placed in an unsealed container of water, both oxygen and carbon dioxide from the atmosphere can enter the water. This creates conditions under which rust can form.
According to Scientist 2, water must contain oxygen and acid in order for rust to form. However, Scientist 2 says that even when no acid is directly added to water, carbon dioxide from the air can react with water to form carbonic acid. Oxygen can also dissolve from the air into the water. So, if an iron pot is placed in an unsealed container of water, both oxygen and carbon dioxide from the atmosphere can enter the water. This creates conditions under which rust can form.
Compare your answer with the correct one above
In its refined form, iron is a shiny, silver-gray metal; however, when refined iron is exposed to atmospheric conditions for an extended period of time, its surface becomes flaky, pitted, and red- or orange-colored. This process is known as "rusting," and the new flaky, orange or red substance is called "rust."
Below, two scientists discuss how rust forms and the composition of rust.
Scientist 1:
Both water and oxygen are needed for rust to form. Water is an electrolyte_,_ meaning that it allows ions to move within it. When iron comes into contact with water, some iron naturally dissociates into iron ions (Fe2+) and free electrons. Additionally, when atmospheric oxygen (O2) dissolves in water, some oxygen reacts with water to form hydroxide ions (OH-). Because water allows ions to move freely, iron ions and hydroxide ions combine to form a new compound: iron hydroxide. However, iron hydroxide is not a stable compound. Over time, as water evaporates, it changes into a hydrated form of iron oxide. This is rust.
Salts can act as catalysts for rust formation, meaning that they speed up the rate at which rust forms. However, rust can form in pure water, in the absence of added salts.
Increasing the ambient temperature increases the rate of rust formation. Additionally, increasing the amount of iron's surface area that is exposed to water also increases the rate at which rust forms. However, because a layer of rust is porous to water and oxygen, water and oxygen will continue to cause the interior of a piece of iron to rust even after the iron's surface has been rusted.
Scientist 2:
Attack by acids causes rust to form. In water, acids ionize to create positively-charged hydronium (H+) ions and negatively-charged anions. Hydronium ions are electron-deficient; because of this, they attract electrons from iron. This creates iron ions (Fe2+), which are soluble in water. Once dissolved in water, iron ions react with dissolved atmospheric oxygen (O2) to create iron oxide, or rust.
Acids can come from a variety of sources. For example, when carbon dioxide in the atmosphere dissolves in water, carbonic acid (H2CO3) is created. Carbonic acid is the most common cause of rusting. However, other environmental sources of acids exist. Rainwater is normally slightly acidic because it has come into contact with molecules in the atmosphere, like sulfur dioxide and nitrogen oxides. These molecules also dissolve in water to form acids. Additionally, iron itself may contain impurities such as phosphorous and sulfur, which react with water to produce acids. Both acidic environments and impurities within iron itself create the conditions under which iron rusts.
Rusting can be prevented by painting the surface of iron, thus preventing it from coming into contact with water, oxygen, and acids. Iron can also be protected in a process called "galvanizing," which involves coating iron in a thin layer of zinc. Because zinc is more reactive than iron, it is corroded while the iron is protected.
Bromothymol blue is a pH indicator that is yellow in acidic solutions and blue in basic solutions. When bromothymol blue is added to a solution, it remains blue. A piece of iron is then immersed in this solution. Given that the explanation of Scientist 2 is correct, which of the following is most likely to occur?
In its refined form, iron is a shiny, silver-gray metal; however, when refined iron is exposed to atmospheric conditions for an extended period of time, its surface becomes flaky, pitted, and red- or orange-colored. This process is known as "rusting," and the new flaky, orange or red substance is called "rust."
Below, two scientists discuss how rust forms and the composition of rust.
Scientist 1:
Both water and oxygen are needed for rust to form. Water is an electrolyte_,_ meaning that it allows ions to move within it. When iron comes into contact with water, some iron naturally dissociates into iron ions (Fe2+) and free electrons. Additionally, when atmospheric oxygen (O2) dissolves in water, some oxygen reacts with water to form hydroxide ions (OH-). Because water allows ions to move freely, iron ions and hydroxide ions combine to form a new compound: iron hydroxide. However, iron hydroxide is not a stable compound. Over time, as water evaporates, it changes into a hydrated form of iron oxide. This is rust.
Salts can act as catalysts for rust formation, meaning that they speed up the rate at which rust forms. However, rust can form in pure water, in the absence of added salts.
Increasing the ambient temperature increases the rate of rust formation. Additionally, increasing the amount of iron's surface area that is exposed to water also increases the rate at which rust forms. However, because a layer of rust is porous to water and oxygen, water and oxygen will continue to cause the interior of a piece of iron to rust even after the iron's surface has been rusted.
Scientist 2:
Attack by acids causes rust to form. In water, acids ionize to create positively-charged hydronium (H+) ions and negatively-charged anions. Hydronium ions are electron-deficient; because of this, they attract electrons from iron. This creates iron ions (Fe2+), which are soluble in water. Once dissolved in water, iron ions react with dissolved atmospheric oxygen (O2) to create iron oxide, or rust.
Acids can come from a variety of sources. For example, when carbon dioxide in the atmosphere dissolves in water, carbonic acid (H2CO3) is created. Carbonic acid is the most common cause of rusting. However, other environmental sources of acids exist. Rainwater is normally slightly acidic because it has come into contact with molecules in the atmosphere, like sulfur dioxide and nitrogen oxides. These molecules also dissolve in water to form acids. Additionally, iron itself may contain impurities such as phosphorous and sulfur, which react with water to produce acids. Both acidic environments and impurities within iron itself create the conditions under which iron rusts.
Rusting can be prevented by painting the surface of iron, thus preventing it from coming into contact with water, oxygen, and acids. Iron can also be protected in a process called "galvanizing," which involves coating iron in a thin layer of zinc. Because zinc is more reactive than iron, it is corroded while the iron is protected.
Bromothymol blue is a pH indicator that is yellow in acidic solutions and blue in basic solutions. When bromothymol blue is added to a solution, it remains blue. A piece of iron is then immersed in this solution. Given that the explanation of Scientist 2 is correct, which of the following is most likely to occur?
Scientist 2 states that rusting is caused by attack by an acid. If he is right, rust can form in acidic solutions, but will not form in basic solutions. This question tells us that the blue color of bromothymol blue shows that a solution is basic. Since the bromothymol blue keeps its blue color, we know that the solution in the question is basic. So, rust will most likely not be formed.
Scientist 2 states that rusting is caused by attack by an acid. If he is right, rust can form in acidic solutions, but will not form in basic solutions. This question tells us that the blue color of bromothymol blue shows that a solution is basic. Since the bromothymol blue keeps its blue color, we know that the solution in the question is basic. So, rust will most likely not be formed.
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