3.1.5 Kinetics

Question 1

What must particles do in order to react?

Answer 1

Collide with sufficient energy (activation energy) and the correct orientation.

Question 2

Do most collisions result in a reaction?

Answer 2

No

Question 3

Define activation energy

Answer 3

The minimum energy that particles must collide with for a reaction to occur

Question 4

Draw a labelled Maxwell-Boltzman Curve. Label average energy, activation energy and most probable energy. Draw in a different colour the effect of increasing temperature.

Answer 4

Question 5

What is the effect of increasing temperature on rate of reaction? Why?

Answer 5

Increasing temperature -> increased rate of reaction
- Much higher proportion of particles have energy greater than the activation energy -> many more successful collisions per second -> increased rate

Question 6

What is the effect of increasing concentration/pressure on rate of reaction? Why?

Answer 6

Increased concentration/pressure -> increased rate of reaction

Question 7

What is a catalyst?

Answer 7

A substance which increases the rate of reaction but is not used up in the reaction

Question 8

How do catalysts work and how do they increase the rate of reaction?

Answer 8

Provide an alternative reaction pathway with lower activation energy
- lowers activation energy, so more particles have energy > activation energy, more frequent successful collisions, so increased reaction rate.