Question
The energies of activation for forward and reverse reactions for A2 + B2 ⇌ 2AB are 180 kJ mol–1 and 200 kJ mol–1 respectively. The presence of a catalyst lowers the activation energy of both (forward and reverse) reactions by 100 kJ mol–1. The enthalpy change of the reaction (A2 + B2 → 2AB) in the
presence of catalyst will be (in kJ mol–1) –
-
300
-
120
-
280
-
-20
Solution
D.
-20
So, ∆ =− HReaction Ef- Eb
= 80 – 100 = -20
