Question

If a given reaction has an activation energy of 102 kJ/mol, what is the activation energy for the reverse reaction?

A) 102 kJ/mol
B) -102 kJ/mol
C) 204 kJ/mol
D) -204 kJ/mol

Answer 1

Without additional data on the enthalpy change of the reaction, the activation energy for the reverse reaction cannot be determined from the given activation energy for the forward reaction.

Step-by-step explanation:

The activation energy for a reverse reaction can be found by considering the difference between the activation energy of the forward reaction and the overall energy change of the reaction. If a reaction has an activation energy (Ea) of 102 kJ/mol for the forward reaction, and assuming no information about the overall energy change (ΔH) for the reaction is provided, we cannot determine the activation energy for the reverse reaction directly from the given information. We would need to know the enthalpy change of the reaction to calculate the activation energy for the reverse reaction because activation energy is a path-dependent property. Therefore, based on the information provided, we cannot choose any of the options A) 102 kJ/mol, B) -102 kJ/mol, C) 204 kJ/mol, or D) -204 kJ/mol without additional data regarding the enthalpy change. Activation energies do not simply reverse sign or double for reverse reactions.