Question

What is the effect of temperature on the rate constant?

Answer 1

Rate constant

• The equation for rate is as follows:-

$\text{Rate}=k{\left[\mathrm{A}\right]}^x{\left[\mathrm{B}\right]}^y$ ......(1)

$-\frac{dR}{dt}=k{\left[A\right]}^x{\left[B\right]}^y$……..(2)

• This form of equation (2) is known as the differential rate equation. Here, k is the rate constant.

Arrhenius equation

According to Arrhenius equation:-

$K=A{e}^{-Ea/RT}$………(3)

Here, A is the Arrhenius factor or the frequency factor. It is also called the pre-exponential factor. R is the gas constant and E_a is the activation energy.

Effect of temperature

• According to the Arrhenius equation(3) increasing the temperature or decreasing the activation energy will result in an increase in the rate of the reaction and an exponential increase in the rate constant.
• It is observed that the Rate Constant of a reaction is doubled when the temperature is increased by ${10}^{°}\text{C}$.