We know that the rate of reaction depends on two things: the rate constant, k and the concentrations of reactants, raised to a power. Since increasing temperature has no change of concentration, thus it effects the value of k. So k is a general measure of the rate of reaction at a particular temperature
16.3.2 Determine activation energy (Ea) values from the Arrhenius equation by a graphical method
This is the Arrhenius equation that links all the factors together.
k is the rate constant
A is the Arrhenius constant
R is universal gas constant
T is temperature (K)
Ea is activation energy
By rearranging it, we could plot it on the graph using linear law.
Thus the graph shall look like this:
The y-axis is ln k
The y-intercept will be ln A
The gradient is Ea/R
Thus finding the gradient will give us Ea/R. Then times the result by the gas constant 8.31 J K^-1 mol^-1 to receive the final answer of Ea.
Ea is in kJ mol^-1
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