M5 Chapter 19 - Equilibrium

Question 1

What does it mean when a reaction is at equilibrium?

Answer 1

The rate of the forward and reverse reactions are equal.

Question 2

What are the methods that can be used to measure equlibrium?

Answer 2

Measure change in colour or colour intensity using colorimeter
pH probe
Measure electrical conductivity
Titration - used when equilibrium is slow.

Question 3

What does mol fraction mean?

Answer 3

The amount of a given component in a given reaction mixture.

Question 4

Write the equation used to calculate mol fraction.

Answer 4

Mol fraction = number of mol of a substance A / total number of mol of all substances

Question 5

What does partial pressure mean?

Answer 5

The pressure exerted by a single species in a reaction vessel.

Question 6

What is the symbol for partial pressure?

Answer 6

P

Question 7

Write down the equation used to calculate partial pressure.

Answer 7

Partial Pressure = mol fraction x total pressure

Question 8

What is the relationship between concentration of a substance and its partial pressure?

Answer 8

Concentration of a substance is proportional to its partial pressure

Question 9

What are the 3 common units of pressure used in chem?

Answer 9

Pascals
Atmospheres
Newtons per sq metre

Question 10

What type of brackets are used in Kc expressions?

Answer 10

Square brackets.

Question 11

What type of brackets are used in Kp expressions?

Answer 11

Round brackets

Question 12

What is the symbol of the equilibrium constant?

Answer 12

k

Question 13

What does it mean when k is greater than 1?

Answer 13

Reaction favours product

Question 14

What does it mean when k is less than 1?

Answer 14

Reaction favours reactants

Question 15

What is the effect of increasing temperature on k?

Answer 15

Equilibrium shifts to the side of endothermic reaction.

Question 16

What is the effect of decreasing temperature on k?

Answer 16

Equilibrium shifts to the side of exothermic reaction.

Question 17

What is the only factor affecting k?

Answer 17

Temperature

Question 18

What is the effect of increasing temperature on k for a forward endothermic reaction?

Answer 18

K increases as temperature increases.

Question 19

What is the effect of increasing temperature on k for a forward exothermic reaction?

Answer 19

K decreases as temperature increases.

Question 20

What affect does a catalyst have on k?

Answer 20

Catalysts do not have an effect on k/position of equilibrium, they only have an effect on the rate of reaction.