Question

For an exothermic reaction
(1) E > ΔΗ
(2) Ε «ΔΗ
(3) Ε =ΔΗ
(4) any one of the above

Answer is 4 but how ? In endothermic reaction E > ΔΗ
What about exothermic ?​

Answer 1

Answer:

1) E > ΔΗ

Activation energy is the minimum quantity of energy which the reacting species must possess in order to undergo a specified reaction.

Ea-Activation energy

Here, energy of products is higher than that of reactants.

This graph is for an endothermic reaction.

△H for an endothermic reaction is positive

See figure above, when the reaction reaches point P, the reactants possess enough energy for the reaction to take place.

In further reaction, some energy is use up for conversion of reactants to products.

This used up energy must be less than Ea, for an endothermic reaction

Since, 

Ea- H = (used up energy)

∴Ea>H

Hence, the activation energy must be more than H