Consider the following transformation involving first order elementary reaction in each step at constant temperature as shown below.
\(\mathrm{A}+\mathrm{B} \underset{\text { Step } 3}{\stackrel{\text { Step } 1}{\rightleftharpoons}} \mathrm{C} \xrightarrow{\text { Step } 2} \mathrm{P} \)
Some details of the above reaction are listed below.
| Step | Rate constant (sec-1) | Activation energy (kJ mol-1) |
| 1 | k1 | 300 |
| 2 | k2 | 200 |
| 3 | k3 | Ea3 |
If the overall rate constant of the above transformation (k) is given as \(k = \frac{k_1k_2}{k_3}\) and the overall activation energy (Ea) is 400 kJ mol–1, then the value of Ea3 is ______ kJ mol–1 (nearest integer)
Enter numerical value using the virtual keypad. Round off where necessary.