Chemistry 202 Class 5- Le Chatelier's Principle & the Connection Between Free Energy and Equilibrium

Increasing concentration of reactants…

Reaction will shift to the right (forward) in order to “use up” the additional reactant, producing more products

Increasing concentration of products…

Reaction will shift to the left (reverse) to use up the added product

Decreasing concentration of reactant…

Reaction will shift left (reverse) to produce more reactants

Decrease concentration of products…

Reaction will shift right (forward) to produce more products

Endothermic and Changing T

K increases as T rises. Why? Think of heat as a reactant- by adding heat, they system will move forward to make more products

Exothermic and Changing T

K increases as T decreases. Why? Think of heat as a product- by removing heat, the reaction will more forward to produce more products

Catalyst and Equilibrium

Catalysts do not impact the position of equilibrium, they can only speed up how fast a reaction reaches equilibrium

Decrease in volume…

The equilibrium will shift to favor the direction that produces fewer moles of gas

Increase in volume…

The equilibrium will shift to favor the direction that produces more moles of gas

Van’t Hoff formula

Van’t Hoff, K, and T

Van’t Hoff allows us to solve for ΔH, which tells us if the reaction is exo or endothermic. With this, we can determine how K will change with changes in T

Standard State

P= 1 atm

T= 25 C (298.15 K)

All concentrations at 1M

Q at standard state

Q=1 AT STANDARD STATE