Unit 7 - Equilibrium

Mr. Germanoski's AP Chemistry

Dynamic Equilibrium

Changing the amount of reactant or product in a reversible reaction will cause the rate and direction to change.

What happens when you add more reactants?

You have more product.

What happens when you have more product?

You have less reactants.

Le Chatelier’s Principle

Changes to a system, such as pressure and quantity will cause the reaction to shift to attain a new equilibrium.

When a substance is added, it causes…

Increase on the other side.

When a substance is removed, it causes…

Increase on the same side.

Adding an inert gas has…

no effect on equilibrium.

Adding a catalyst will…but won’t…

speed up the reaction but won’t affect equilibrium.

If volume decreases then

pressure will increase and the equilibrium shifts towards the side with fewer moles of gas.

Increase in volume then

decrease pressure and equilibrium shifts towards side with more moles.

In exothermic reactions increasing temperature will…

shift towards reactants. (left)

In endothermic reactions increasing temperature will…

shift towards products. (right)

(endothermic) temperature increase, means k…

increases

(endothermic) temperature decrease, means k…

decreases

(exothermic) temperature increase, means k…

decreases

(exothermic) temperature decrease, means k…

increases

Q < K

The reaction shifts right (forward) to make more products

Q > K

It shifts left (reverse) to make more reactants

Q = K

equilibrium

Exothermic

ΔH < 0

Endothermic

ΔH > 0

Molar solubility

maximum number of moles of a solute that can dissolve in one liter of solvent to form a saturated solution at a specific temperature