Rate equations (A-level only)

where m and n are the orders of reaction with respect to reactants A and B and k is the rate constant.

The orders m and n are restricted to the values 0, 1, and 2.

The rate constant k varies with temperature as shown by the equation:

where A is a constant, known as the Arrhenius constant, Eₐ is the activation energy and T is the temperature in K.

Students should be able to:

• define the terms order of reaction and rate constant

• perform calculations using the rate equation

• explain the qualitative effect of changes in temperature on the rate constant k

• perform calculations using the equation $k = A\mathrm{e}^{-E_a/RT}$

• understand that the equation $k = A\mathrm{e}^{-E_a/RT}$ can be rearranged into the form $\ln k = -E_a/RT + \ln A$ and know how to use this rearranged equation with experimental data to plot a straight line graph with slope $-E_a/R$

These equations and the gas constant, R, will be given when required.