1. Chemical Equilibrium AUTHOR: WESLEY TUNG

2. Technical Things

3. Intro to Equilibrium History ◦In 1803, Claude Louis Berthelot, a Savoyard-French chemist, discovered some chemical reactions were reversible. Definition of Equilibrium ◦The state in a chemical reaction in which both products and reactants are present in concentrations that have no further tendency to change over time. Two types of chemical equilibrium exist: ◦Static Equilibrium ◦The reaction is irreversible. ◦Dynamic Equilibrium ◦The reaction is reversible.

4. Reaction Quotient

5. Equilibrium Constant

6. Le Chatelier's Principle History ◦Developed by Henry-Louis Le Chatelier in 1884 to predict the change in disturbed equilibrium systems to re-achieve equilibrium. ◦In general: ◦Increasing the concentration of reactants causes more products to be made (Shift right). ◦Increasing the concentration of products causes more reactants to be made (Shift left). ◦Decreasing the volume but keeping everything else constant would shift the reaction towards the side of the reaction that produces the least total amount of moles. ◦Increasing the volume but keeping everything constant would shift the reaction towards the side of the reaction that produces the most amount of moles.

7. Le Chatelier’s Principle Temperature is unique ◦It doesn’t modify the reactant quotient like volume and concentration but modifies the equilibrium constant. ◦The shift depends on whether the reaction is exothermic or endothermic: ◦Endothermic: Heat is a reactant and the reaction shifts right if you increase the temperature. ◦Exothermic: Heat is a product and the reaction shifts left if you increase the temperature.