Question

For an endothermic reaction energy of activation is E_a and enthalpy of reaction ΔH (both of there in KJ moI^–1) minimum value of E_a will be ______.

Options

• Less than ΔH

• Equal to ΔH

• More than ΔH

• Equal to zero

Answer 1

For an endothermic reaction energy of activation is E_a and enthalpy of reaction ΔH (both of there in KJ moI^–1) minimum value of E_a will be less than ΔH.

Explanation:

For an endothermic reaction

ΔH = E_af – E_ab

E_af = Activation energy for forward reaction

E_ab = Activation energy for backward reaction

or E_af = ΔH + E_ab

So E_a > ΔH