Question

What are the dimensions of $\mathrm{A}$ in the expression $\mathrm{k}={\mathrm{Ae}}^{-{\mathrm{E}}_{\mathrm{a}}/\mathrm{RT}}$?

Answer 1

Arrhenius equation:

• The Arrhenius equation can be expressed as $\mathrm{k}={\mathrm{Ae}}^{-{\mathrm{E}}_{\mathrm{a}}/\mathrm{RT}}$.
• Where $\mathrm{k}$ is the rate of reaction, ${\mathrm{E}}_{\mathrm{a}}$ is the activation energy, $\mathrm{T}$ is the temperature and $\mathrm{R}$ is the gas constant.
• $\text{'}\mathrm{A}\text{'}$in Arrhenius equation represents the Arrhenius constant which is the number of collisions per unit of time.
• The dimension of the Arrhenius equation is collisions per unit which is expressed in ${\mathrm{s}}^{-1}$.
• This equation is used to define the relationship between the rate of reaction with temperature and the pre-exponential factor i.e. $\mathrm{A}$.