Module 12: Kinetics and Equilibrium

When you bake a cake, you add flour, sugar, eggs, oil, and water. Mix these ingredients together with the correct proportions and soon you will have a delicious treat. Why can you not reverse the process? There is no way to deconstruct the cake and get your original ingredients back. The same is true for many chemical reactions. They are simply irreversible.

There are some reactions that reach equilibrium through a forward and reverse process. These reactions are reversible. How can this happen? The reactions are in a dynamic equilibrium where the concentrations of products and reactants can vary. Reversible reactions are defined by the equilibrium constant, abbreviated as K. Le Chatelier’s principle explains how reactions change due to various stressors such as temperature, volume, concentration, or pressure to remain at equilibrium. This module will explain both concepts of reaction rate and equilibrium.

Getting Started

Did you know that chemistry is used in eyeglasses that change tint with varying levels of sunlight? The lenses of these eyeglasses have the added compounds of copper oxide and silver halide. The sunlight causes the two compounds to react, darkening the lenses. When in the shade, the copper oxide and silver halide reverse their reactions to create clear lenses once again. How else does the chemistry of reversible reactions affect our daily lives? Take a few minutes to do some quick internet research to find one reversible reaction that provides a benefit.

 

Key Vocabulary

To view the definitions for these key vocabulary terms, visit the course glossary.

dynamic equilibrium	equilibrium constant	Static equilibrium
equilibrium	Le Chatelier's Principle