Consider the following transformation involving first order elementary reaction in each step at constant…
Consider the following transformation involving first order elementary reaction in each step at constant temperature as shown below.
$A+B \xrightarrow[\text{Step 3}]{\text{Step 1}} C \xrightarrow{\text{Step 2}} P$
Some details of the above reactions are listed below.
$\begin{aligned}
&\begin{array}{ccc}
\text{Step} & \text{Rate constant }(s^{-1}) & \text{Activation energy }(kJ~mol^{-1}) \\
1 & k_{1} & 300 \\
2 & k_{2} & 200 \\
3 & k_{3} & Ea_{3}
\end{array}
\end{aligned}$
If the overall rate constant of the above transformation $(k)$ is given as $k=\frac{k_{1}k_{2}}{k_{3}}$ and the overall activation energy $(E_{a})$ is $400~kJ~mol^{-1}$, then the value of $Ea_{3}$ is $\qquad kJ~mol^{-1}$ (nearest integer)