1. Le Chatelier’s Principle
Main Concept:
Systems at equilibrium respond to disturbances by partially countering the effect of the disturbance (Le Chatelier’s principle).

2. Le Chatelier’s Principle
Le Chatelier’s Principle Purpose
Stress Effect/Shift
Addition/Removal of
Chemical Species
Volume/Pressure Changes
Temperature Changes

3. - Le Chatelier’s principle can be used to predict the response of a system to stresses: addition or removal of a chemical species, change in temperature, change in volume/pressure of a gas phase system, and dilution of a reaction system with water or other solvent

4. - Le Chatelier’s principle can be used to reason about the effects a stress will have on experimentally measurable properties, such as pH, temperature, and color of a solution

5. Le Chatelier’s Principle Rules:
Adding chemical species: shifts equilibrium away from chemical species side
Removing chemical species: shifts equilibrium towards chemical species side
Increasing pressure (decreasing volume): shifts equilibrium towards side with less moles
Decreasing pressure (increasing volume): shifts equilibrium towards side with more moles

6. Le Chatelier’s Principle Rules:
Increasing Temperature:
Endothermic Reactions: shifts equilibrium towards products
Exothermic Reactions: shifts equilibrium towards reactants
Decreasing Temperature:
Endothermic Reactions: shifts equilibrium towards reactants
Exothermic Reactions: shifts equilibrium towards products