Using Moles - High School Chemistry
Card 0 of 4
Consider the following four samples:
of potassium
of lithium
of magnesium
of chlorine gas
Which of the given samples contains the most atoms?
Consider the following four samples:
Which of the given samples contains the most atoms?
It is important to note that the mass of a sample does not tell you the amount of atoms in the sample. The number of atoms in a sample is dependent on the number moles in a sample, given by Avogadro's number. Here is the number of moles for each sample:
Remember that chlorine is a diatomic mass, so each molecules contains two atoms. This doubles the molar mass for the conversion.
The sample with the greatest number of moles will also contain the most atoms. In this case, the sample of lithium results in the largest number of moles and, thus, the greatest number of atoms.
It is important to note that the mass of a sample does not tell you the amount of atoms in the sample. The number of atoms in a sample is dependent on the number moles in a sample, given by Avogadro's number. Here is the number of moles for each sample:
Remember that chlorine is a diatomic mass, so each molecules contains two atoms. This doubles the molar mass for the conversion.
The sample with the greatest number of moles will also contain the most atoms. In this case, the sample of lithium results in the largest number of moles and, thus, the greatest number of atoms.
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Convert the following amount from grams (g) to moles (m)
How many moles is 
of 
?
Convert the following amount from grams (g) to moles (m)
How many moles is
Use the periodic table to calculate the molecular weight of sodium hydroxide.
Next, use dimensional analysis to find the number of moles.
Use the periodic table to calculate the molecular weight of sodium hydroxide.
Next, use dimensional analysis to find the number of moles.
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Consider the reaction above. If you start with 
of potassium bromide, how many moles of bromine are produced? How many molecules is this equal to?
Consider the reaction above. If you start with
In the chemical equation, the ratio of potassium bromide to bromine is 2:1, so for every 2 moles of 
, 1 mole of 
is produced. Therefore, if we start with 4 moles of 
, we get 2 moles of 
. The number of molecules is equal to the number of moles times Avogadro's Number. Since we've determined the number of moles to be 2, the number of molecules is:
In the chemical equation, the ratio of potassium bromide to bromine is 2:1, so for every 2 moles of
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How many moles of 
are present in 
of the substance?
How many moles of
The molecular weight of carbon dioxide is 
, meaning in 
of 
, there are 
of the substance.
The molecular weight of carbon dioxide is
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