Kinetics

Question 1

Rate of reaction -

Answer 1

Rate of reaction tells us how quickly a chemical reaction is happening.

Question 2

How do we measure rate of reaction? Practically.

Answer 2

• Concentration increases in a product;
• Mass of reactants decreases;
• Gas being produced.

Question 3

Collision theory*:

Answer 3

• Particles must collide;
• Particles must have sufficient energy to collide;
• Particles must collide at the correct orientation.

Question 4

What is meant by correct orientation? Understanding check:3

Answer 4

Correct orientation means that particles are in needed positions for a reaction to occur.

Question 5

Factors that affect the rate of reaction:

Answer 5

• Concentration;
• Volume;
• Temperature;
• Pressure;
• Catalyst

Question 6

How does concentration affect the rate of reaction?

Answer 6

Increasing the concentration increases the amount of particles in a given volume, therefore more successful collisions can occur and that increases the rate of reaction.

Question 7

How does Volume affect the rate of reaction?

Answer 7

Similarly to concentration, decreasing the volume increases the amount of particles in a given volume, therefore more successful collisions occur and that speeds up the reaction.

Question 8

How does Temperature affect the rate of reaction?

Answer 8

Increasing the temperature increases the energy particles have and they move faster, moving faster increases the chance of successful collisions and the amount of particles with sufficient energy to react as well, that increases the rate of reaction.

Question 9

How does a Catalyst affect the rate of reaction?

Answer 9

Catalysts role in a reaction is to lower the energy needed for a successful collisions and therefore increase the amount of particles that have such, Catalyst is not used up in the reaction.

Question 10

What is a homogeneous and a heterogeneous catalyst?

Answer 10

Homogeneous catalyst - a type of catalyst that is being in the same phase (‘state’) as the reactants.
Heterogeneous catalyst- a type of a catalyst that is being in a different phase (‘state’) to the reactants.

Question 11

Boltzmann distribution -

Answer 11

Boltzmann distribution is a graph that shows the number of particles which have and don’t have a sufficient energy to react.

Question 12

How do
- Temperature
- Concentration
- Catalyst
affect Boltzmann’s graph

Answer 12

1. Raising the temperature lowers the curve of the graph but increases the amount of particles that have enough energy to react.
2. Increasing the concentration increases the overall amount of particles and therefore increases the amount of particles that have a sufficient energy to react.
3. Adding a Catalyst will lower the activation energy and more particles will have enough energy to react.