Question

For the reaction, for which the activation energies for forward and backward reactions are same, then:

A. ΔH=0
B. ΔS=0
C. the order is zero
D. there is no catalyst

Answer 1

The correct option is A. ΔH=0. When the activation energies for the forward and backward reactions are the same, it means that the rate constants for the two reactions are equal. This is known as detailed balance condition, and it occurs when the reaction is at equilibrium.

Step-by-step explanation:

The correct option is A. ΔH=0. When the activation energies for the forward and backward reactions are the same, it means that the rate constants for the two reactions are equal. This is known as detailed balance condition, and it occurs when the reaction is at equilibrium. At equilibrium, the change in enthalpy (ΔH) is zero, since the reaction is balanced and there is no net energy change. Therefore, option A is correct.

Additionally, the activation energy remains the same regardless of the presence or absence of a catalyst. The catalyst only provides an alternative reaction pathway with a lower activation energy, but it does not impact the equilibrium or the change in enthalpy. Therefore, options B, C, and D are not correct in this context.