IGCSE Edexcel- Chemistry: Factors affecting Rates of Reaction

Question 1

Concentration

Answer 1

More particles per unit volume
Therefore more collisions per unit time
Therefore more successful collisions per unit time
RoR increases

Question 2

Surface Area

Answer 2

More surface exposed
More surface for particles to react on
Therefore more collisions per unit time
Therefore more successful collisions per unit time
RoR increases

Question 3

Temperature

Answer 3

Higher temperature
Particles gain KE
Therefore more collisions per unit time
Therefore more successful collisions per unit time
RoR increases

Question 4

Catalyst

Answer 4

Provides alternate route with lower activation energy
Since more particles energy >= new Ea
More successful collisions per unit time
Rate of reaction increases