C7 Rates of Reaction and Energy Changes

Question 1

What is activation energy?

Answer 1

The minimum energy that particles need to react when they collide

Question 2

What happens to the rate if you increase the temperature?

Answer 2

1. Particles have more kinetic energy
2. Frequency of collisions increases
3. Frequency of successful collisions increases

Question 3

What happens to the rate if you use smaller solid particles?

Answer 3

1. Larger surface area to volume ratio so more particles available to collide
2. Frequency of collisions increases
3. Frequency of successful collisions increases

Question 4

What happens to the rate if you increase the concentration/pressure?

Answer 4

1. More particles per unit volume
2. Frequency of collisions increases
3. Frequency of successful collisions increases

Question 5

What is a catalyst?

Answer 5

A substance which increases the rate of reaction by lowering the activation energy without being used up in the reaction

Question 6

What is an exothermic reaction?

Answer 6

A reaction that gives out energy to the surroundings

Question 6

What is an endothermic reaction?

Answer 6

A reaction which takes in energy from surroundings