ES - Equilibrium

Question 1

What is a reversible reaction?

Answer 1

A reaction that can go both ways.

Question 2

What happens to the forward reaction as the reactants get used up?

Answer 2

Slows down.

Question 3

What happens to the reverse reaction as more product is formed?

Answer 3

Speeds up.

Question 4

What is dynamic equilibrium?

Answer 4

When the rate of the forward reaction is going at the same rate as the backward reaction.

Question 5

What is it called when the rate of the forward reaction is going at the same rate as the backward reaction.

Answer 5

Dynamic equilibrium.

Question 6

Were can a dynamic equilibrium occur?

Answer 6

In a closed system as nothing can get in or out.

Question 7

What does the position of the equilibrium tell you?

Answer 7

How much reactant and product you’ll have at equilibrium.

Question 8

What will there be more of in a reaction if the equilibrium lies to the left?

Answer 8

More reactants than products.

Question 9

What will there be more of in a reaction if the equilibrium lies to the right?

Answer 9

More products than reactants.

Question 10

What is the equilibrium constant?

Answer 10

The ratio of the conc. of the products:the conc. of the reactants at a given temperature.

Question 11

What can the equilibrium constant tell you about?

Answer 11

The position of the equilibrium.

Question 12

If the equilibrium constant is a large number, what is there a lot of?

Answer 12

Products.

Question 13

If the equilibrium constant is 1, what is the reaction like?

Answer 13

Balanced.

Question 14

If the equilibrium constant is a small number, what is there a lot of?

Answer 14

Mainly reactants.

Question 15

What does decreasing the reactants do to the equilibrium?

Answer 15

Makes it shift to the left.

Question 16

Can the equilibrium constant be negative?

Answer 16

No.

Question 17

What do you need to calculate the exact value of the equilibrium constant?

Answer 17

The equilibrium concentrations (and a calculator!!).

Question 18

What does changing the concentrations of reagents do to the equilibrium constant?

Answer 18

Nothing.

Question 19

What happens if you change the concentrations of the reactants or products?

Answer 19

The position of the equilibrium will shift to keep the equilibrium constant CONSTANT.

Question 20

How does changing the pressure alter equilibrium position?

Answer 20

ONLY AFFECTS EQUILIBRIA INVOLVING GASES!

Increasing the pressure shifts the equilibrium to the side with fewer gas molecules - this reduces the pressure.

Decreasing the pressure shifts the equilibrium to the side with more gas molecules - this raises the pressure again.

Question 21

How does changing the temperature alter the equilibrium position?

Answer 21

Increasing the temperature means adding heat. The equilibrium will shift in the endothermic (positive enthalpy change) direction to absorb this heat.

Decreasing the temperature removes heat. The equilibrium shifts in the exothermic (negative enthalpy change) direction to try to replace the heat.

(If the forward reaction is endothermic, the reverse reaction will be exothermic, and vise versa.)

Question 22

What are the characteristics of dynamic equilibrium?

Answer 22

Concentrations of products and reactants stay constant.

Forwards and reverse reaction are both happening.

The rate of forward and reverse reactions are equal to each other.