The Rate Equation

The rate equation is used to show the effect of changing the concentration of different reactants on the rate of reaction.

Rate = k[A] [B]

Key:
Rate – This is the overall rate of the reaction.
A/B- Reactants
k – The rate constant.
– The reaction orders.
The Rate
The rate of reaction is the rate of which the reactants are turned into products. The rate can be changed by:
Changing theTemperature.
Adding aCatalyst.
Changing the Surface Areaof the reactants.
Changing the Concentration of the reactants.
The Rate Constant(k)
The rate constant is also known as the ‘rate coefficient’ and it varies with different reactions and conditions. For the same reaction it can be effected by:
The Temperature
ACatalyst
Surface areaof reactants.
The constant varies from reaction to reaction due to the different bond strengths, number of steps/intermediates and the activation energy.
Rate Orders
Rate orders show how much of an effect changing the concentration of a reactant will have on the rate of the reaction.
A Zero order reactant will have no effect on the rate if it is changed.
A First order reactant will have a proportional effect on rate if the concentration is changed.
A Second order reactant will have the effect of squaring the rate if the concentration is changed.