JEE Main Chemistry question
The activation energies of forward and backward reaction: 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 backward) reactions by 100 kJ mol⁻¹. The enthalpy change of the reaction in presence of catalyst will be (in kJ mol⁻¹):
Answer: (A)
Solution
ΔH = Ea(f)−Ea(b) = 180−200 = −20 kJ; a catalyst does not change ΔH.