Rates Of Reaction Definitions

Question 1

Define reaction rate.

Answer 1

Reaction rate is defined as the change in concentration per unit time of either a reactant or product.

Question 2

List the factors that affect rate of reaction.

Answer 2

Nature of reacting substances. Surface area of a solid, concentration of a solution, pressure of a gas, temperature and catalyst.

Question 3

Define catalyst.

Answer 3

A catalyst is defined as a substance that increases the rate of the reaction but remains unchanged at the end if the reaction.

Question 4

Explain collision theory.

Answer 4

Collision theory is a model that explains that a reaction will only proceed when reactant particles collide effectively. An effective collision is one in which the colliding reactant particles have:

• the correct orientation
• sufficient energy (ie kinetic energy equal to or greater than the activation energy.

Question 5

Explain the relationship between rate of reaction and the number of effective collisions per unit time.

Answer 5

Directly proportional.