Le Chatelier's Principle

State Le Chatelier's Principle.

If a stress is applied to a system at equilibrium, the equilibrium shifts to relieve that stress.

Name 3 types of stresses

1) Temp

2) Pressure (gasses)

3) Concentration

How is equilibrium defined?

When the rate of the forward reaction equals the rate of the reverse reaction.

What happens to equilibrium when you add reactants?

The equilibrium shifts to the right (product)

What happens to equilibrium when you remove reactants?

The equilibrium shifts to the left (reactant)

If heat is a product, then the reaction is ...(exo or endothermic)?

Exothermic

If heat is a reactant, then the reaction is exo or endothermic?

Endothermic

If heat is added is exo or endothermic reaction favored?

Endothermic

Suppose one side of the equilibrium equation has more moles of gas than the other. To which side does equilibrium shift when the pressure increases? To the side with more moles of gas or less moles of gas?

The side with less moles.

Suppose one side of the equilibrium equation has more moles of gas than the other. To which side does equilibrium shift when the pressure decreases? To the side with more moles of gas or less moles of gas?

The side with more moles.

If gasses have equal numbers of moles on each side, then how does changing pressure effect equilibrium?

Has no effect

What is a reaction that goes to completion?

When almost all of the ions are removed from solution.

Name three types of reactions that go to completion.

1) Formation of a gas

2) Formation of a precipitate

3) Formation of slightly ionized products

Define the common-ion effect

When the addition of an ion common to two solutes brings about precipitation or reduced ionization.

Why is the addition of a weak electrolyte of an ion species to a solution an example of the common-ion effect?

The electrolyte increases the ionic concentration which react with more ions reducing the number of free ions.