Question

$N_2+3H_2\rightleftharpoons 2N{H}_3+22$kcal
The activation energy for the forward reaction is $50$kcal. What is the activation energy for the backward reaction?

• A. $-72$ kcal
• B. $-28$ kcal
• C. $+28$ kcal
• D. $+72$ kcal

Answer 1

The correct option is D $+72$ kcal

$N_2\left(g\right)+3H_2\left(g\right)\rightleftharpoons 2N{H}_3\left(g\right)+22$kcal

As there is 22Kcal heat is released so its exothermic.

$\because$ The activation energy for the forward reaction $=50$kcal

$\therefore$ The activation energy for the backward reaction $=50+22=+72$kcal.