1.05 Kinetics

Question 1

What must particles do in order to react ?

Answer 1

Collide with sufficient energy (Ea) and in the correct orientation.

Question 2

Do most collisions result in a reaction ?

Answer 2

No

Question 3

Define activation energy (Ea).

Answer 3

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

Question 4

Draw / describe a labelled Maxwell-Boltzmann. Label the average energy, activation energy and most probably energy. Draw / describe how it changes depending on temperature.

Question 5

What is the effect of increasing the temperature on a reaction ?

Answer 5

•Increasing the temperature in increases the rate of reaction
•This is because the frequency of successful collisions increases as a much higher portion of particles have sufficient energy.

Question 6

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

Answer 6

•It results in a faster rate of reaction
•This is because there are more particles in a given volume, which means there are more frequent successful collisions.

Question 7

What is a catalyst ?

Answer 7

A substance which lowers the activation energy of a reaction whilst not being used as a reactant.

Question 8

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

Answer 8

•Catalysts provide an alternative pathway for the reaction (one with a lower Ea)
•The lower Ea means a higher portion of particles have sufficient energy to react, so successful collisions become more frequent, giving a higher rate.