JEE Main 2024 (4 Apr, Shift 1) Chemistry Q85: Consider the…

Question

Consider the following transformation involving first order elementary reaction in each step at constant temperature as shown below.
$\mathrm{A + B} \underset{	ext{Step 3}}{\overset{	ext{Step 1}}{ightleftharpoons}} \mathrm{C} \xrightarrow{	ext{Step 2}} \mathrm{P}$
Some details of the above reactions are listed below.
Step | Rate constant ($\mathrm{sec^{-1}}$) | Activation energy ($\mathrm{kJ\ mol^{-1}}$)
1 | $\mathrm{k_1}$ | 300
2 | $\mathrm{k_2}$ | 200
3 | $\mathrm{k_3}$ | $\mathrm{Ea_3}$
If the overall rate constant of the above transformation (k) is given as $\mathrm{k} = \frac{\mathrm{k_1 k_2}}{\mathrm{k_3}}$ and the overall activation energy ($\mathrm{E_a}$) is 400 $\mathrm{kJ\ mol^{-1}}$, then the value of $\mathrm{Ea_3}$ is ________ $\mathrm{kJ\ mol^{-1}}$ (nearest integer)

Accepted Answer

100

JEE Main 4 April 2024, Shift 1, Chemistry Q85

Same idea in other shifts