Physical Chemistry

Physical Chemistry explores the principles of chemistry and physics to understand the behavior of matter at a molecular and atomic level.

Advanced Topics

Chemical Equilibrium

Striking a Balance

Chemical equilibrium is when a reversible reaction happens at the same rate in both directions, so the amounts of reactants and products stay constant over time.

Dynamic But Stable

Even though the reaction appears still, reactants are turning into products and vice versa at equal rates. This is called dynamic equilibrium.

Le Châtelier's Principle

If you disturb an equilibrium (by changing concentration, temperature, or pressure), the system will adjust to counteract the change.

Equilibrium Constant

The ratio of product concentrations to reactant concentrations at equilibrium is called the equilibrium constant (\(K\)):

\[ K = \frac{[\text{Products}]}{[\text{Reactants}]} \]

Real-World Importance

  • Industrial ammonia production (Haber process)
  • The balance of oxygen and carbon dioxide in your blood

Examples

  • Sealed soda bottles show equilibrium between dissolved and gaseous CO₂.

  • Changing the temperature of a reaction can shift the balance of products and reactants.

In a Nutshell

At equilibrium, reactions happen in both directions at equal rates, keeping concentrations stable.