Question

$N _{2}(g)+3 H _{2}(g) \rightleftharpoons 2 NH _{3}(g)+22\, kcal$. 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

Answer: (D)

+72 kcal

Answer 2

$N _{2}(g)+3 H _{2}(g) \rightleftharpoons 2 NH _{3}(g)+22\, kcal$ $\because$ The activation energy for the forward reaction $=50\, kcal$ $\therefore$ The activation energy for the backward reaction $=50+22=72\, kcal$