AP Chemistry Equilibrium test

Which species are excluded from the equilibrium constant expression?

Pure solids (s) and pure liquids (l) are omitted.

What does a large K value (K≫1) indicate?

The reaction is product-favored, and equilibrium lies to the right.

What does a small K value (0<K≪1) indicate?

The reaction is reactant-favored, and equilibrium lies to the left.

What is the reaction quotient (Q)?

Q is calculated like K but uses initial concentrations to predict the direction of the reaction shift.

What happens when Q<K?

The reaction proceeds forward (right) toward products.

What happens when Q>K?

The reaction proceeds in reverse (left) toward reactants.

What does Le Chatelier's Principle state?

An equilibrium system responds to disturbances to re-establish equilibrium.

What is the effect of adding a reactant on equilibrium?

It shifts the equilibrium to the right.

What is the effect of decreasing volume on a gaseous equilibrium?

It shifts the equilibrium toward the side with fewer moles of gas.

How does temperature affect K for exothermic reactions?

Increasing temperature shifts equilibrium left and decreases K.

What is Ksp?

The solubility product constant, indicating how much of a solid salt will dissolve into ions.

What does it mean if Qsp > Ksp?

The solution is supersaturated, and a precipitate will form.

What is the common ion effect?

The solubility of a salt decreases when a common ion is present in the solution.

What is the relationship between ΔG and K?

ΔG = -RTlnK; if ΔG is negative, K > 1 (product-favored).

What happens to K when a reaction is reversed?

Knew=1/Kold

What's a common ion?

An ion that is already present in present in a solution when a second, less soluble salt containing the same ion is added.