3.5 Chemical Kinetics

Question 1

What are factors that need to happen for a reaction to occur

Answer 1

In order for a reaction to occur between atoms, molecules or ions, the reactants must collide with the correct orientation and with significant energy.

Question 2

How does concentration affect ROR

Answer 2

Increases reaction rate due to an increase in reactant particles in the same volume, so they collide and react more frequently.

Question 3

How does pressure affect ROR

Answer 3

Molecules are closer together in a given volume so they collide and react more frequently.

Question 4

How does surface areaA affect ROR

Answer 4

Increases reaction rate as there is greater contact between reactants, so more collisions take place per second.

Answer 5

Increases reaction rate as there is greater contact between reactants, so more collisions take place per second.

Question 6

What are methods of measuring ROR

Answer 6

Measuring gas volume
(at constant pressure) using a gas syringe.
can only be used when a gas is produced in a reaction.

Measuring gas pressure (at constant volume) – used when both reactants and products are gases and the pressure changes as the number of gas molecules changes.

Measurement of change in mass
– used when a dense gas is produced during a reaction.

Colorimetry
– used when something with colour is produced or used up during a reaction.

Sampling and quenching