Topic 8 - Reaction Kinetics

Question 1

Define

Actiavtion energy

Answer 1

minimum amount of energy required for a collison to be effective

Question 2

How does heat affect the rate of reaction

Boltzmann Distribution

Answer 2

It increases the number of particles with the actiavtion energy and above, leading to an increase in the number of effective collisions and also speeds up the particles leading to a larger number of collisons per unit time, so the chance of a successful collision increases

increased area before the Ea

Question 3

How does a catalyst affect rate of reaction

Boltzmann distribution

Answer 3

shifts Ea to the left thereby lowering the activation energy so there are more particles to the left of the new Ea

Question 4

Describe

Types of catalysts

Answer 4

Homogenous - they are in the same phase as the reactants
Heterogenous - Different phase as the reactants

Question 5

Factors affecting Rate of Reaction

Answer 5

Concentration
Pressure
Size of particles
Surface area
Temperature
Presence of a catalyst

Question 6

How do concentration and pressure increase rate of reaction?

Answer 6

Number of particles per unit volume increased, collision frequency increases so the number of successful collisions increases

Question 7

How does temperature affect rate of reaction ?

Answer 7

Increases
• Particles gain KE and move faster
• More collisions have the activation energy or more
• proportion of successful collisions increases

Question 8

What is a catalyst?

Answer 8

A substance that increases the rate of reaction without itself being chemically altered