Question

What is the slope of the Arrhenius plot?

Answer 1

Arrhenius plot:

1. It explains the temperature dependence of the rate of reaction which shows a relationship between the temperature and the reaction rate constant.
2. According to Arrhenius, the reaction takes place between the reactants to form unstable intermediates.
3. It is based on the collision theory which states that the collision of particles takes place at proper orientation and with enough energy.
4. The general equation of the Arrhenius plot is:
   $\mathrm{k}={\mathrm{Ae}}^{\raisebox{1ex}{$-{\mathrm{E}}_{\mathrm{a}}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{RT}$}\right.}$.
5. The activation energy (${\mathrm{E}}_{\mathrm{a}}$) is the minimum energy that possesses in order to react which forms a product.
6. Pre-exponential factor ($\mathrm{A}=\mathrm{p}\times \mathrm{z}$): It is related to the number of times molecules hit in the orientation which is necessary to cause a reaction where p is the steric factor and Z is the collision frequency.
7. The Arrhenius plot is shown below:

Slope:

1. The slope is used to find out the activation energy.
2. The slope is the ratio of the negative activation energy and gas constant which is represented as: $\frac{-{\mathrm{E}}_{\mathrm{a}}}{\mathrm{R}}$.