Reaction Kinetics

Question 1

What are the 2 conditions for an effective collision?

Answer 1

Correct orientation
Energy equal to or greater than the activation energy

Question 2

Define activation energy.

Answer 2

The minimum amount of energy required for a collision to be effective.

Question 3

Describe the collision theory.

Answer 3

1. Temperature
   - Increasing temperature results in an increase in kinetic energy, which results in more effective collisions
2. Concentration/Pressure (gases)
   - The greater the number of particles per unit volume, the greater the number of effective collisions
3. Catalyst
   - A catalyst lowers the activation energy by providing an alternative reaction mechanism
4. Surface area
   - Increasing surface area results in more of the reactants being exposed
5. Nature of reactants
   - Covalent compounds react slower than ionic ones

Question 4

Name and describe the 2 types of catalysts.

Answer 4

Homogenous catalyst - catalyst is in the same phase
Heterogenous catalyst - catalyst is not in the same phase

Question 5

Define autocatalytic reaction.

Answer 5

The product of the reaction acts as a catalyst.

Question 6

Describe the Boltzmann Distribution.

Answer 6

A Maxwell-Boltzmann distribution curve is a graph that shows the distribution of energies at a certain temperature.

When temperature changes, the spread of values will increase, resulting in an increase in reaction rate as a greater portion of the molecules have energy greater than or equal to the activation energy.

Adding a catalyst shifts the activation energy line to the left, thus more particles have sufficient energy.

Important features:
Never touches the x-axis because no molecules have 0kJ of energy
No maximum energy for the molecules
Area under the curve is equal to the total number of molecules
Only molecules with energy greater than activation energy can react