C6 - The rate and extent of chemical change

Question 1

How is rate of reaction calculated?

Answer 1

quantity of reactant used/time taken or quantity of product formed/time taken

Question 2

What is the unit of rate of reaction?

Answer 2

g/s or cm^3/s

Question 3

What are the four factors affecting rate of reaction?

Answer 3

· Temperature
· Concentration/pressure
· Surface area
· Catalyst

Question 4

Explain how temperature affects rate of reaction

Answer 4

Particles have more kinetic energy, so they travel at a higher speed. This results in the occurrence of more successful collisions per unit time.

Question 5

Explain how concentration/pressure affects rate of reaction.

Answer 5

There are more particles in a fixed volume so more successful collisions occur per unit time.

Question 6

Explain how surface area affects rate of reaction.

Answer 6

There are more surfaces to react on so there are more successful collisions per unit time.

Question 7

Explain how catalysts affect rate of reaction.

Answer 7

Catalysts decrease activation energy by providing an alternate route through which the reaction takes place.

Question 8

Define activation energy.

Answer 8

The minimum amount of energy that particles must have to react.

Question 9

Define equilibrium.

Answer 9

When the forwards and backwards reactions occur at the same rate in a closed system.