Ch. 16 Equilibrium

Question 1

What is the main idea/definition of Equilibrium? (also known as Dynamic Equilibrium)

Answer 1

Changes in reaction, forward and reverse are equal.

Rate Forward Rxn== Rate Reverse Rxn.

Question 2

What does the Equilibrium Constant (K) value show?

Answer 2

K>1 - Rxn is product favored, forward rxn goes until essentially complete.
K<1 - Rxn is reaction favored (or reverse reaction favored), forward rxn does not proceed too far.
K=1 (very close to 1) - neither direction is favored, forward rxn goes about half way.

Question 3

What does an ICE Table help to do?

Answer 3

ICE tables help to solve equilibrium concentrations of reactants and products in a rxn at equilibrium. By making the equations much more algebra based.

Question 4

What is the Reaction Quotient (Qc)?

Answer 4

A ratio of the concentrations of products divided by the concentrations of reactants. (at any point in the rxn)

Question 5

What does the Law of Mass Action show?

Answer 5

The relationship between balanced chemical equations and the equilibrium constant (K).

Question 6

What does Q vs K tell us?

Answer 6

If Q=K , the rxn is at equilibrium!
If Q>K , reaction goes left; Products must be converted into reactants.
If Q

Question 7

What does the Small Change approximation help solve?

When can we do this? (equation)

Answer 7

If there is a small enough change in a concentration (relative to the equilibrium constant (K)) we can ignore it!
When K x 100< [A]

Question 8

When can you avoid having to use the quadratic eqn?

Answer 8

1. When there is a perfect square

2. When you can use the small change approximation