Question

Why does every chemical reaction require a certain amount of activation energy?

A.
Energy is released when the reactants begin to react.
B.
Energy lost to the environment during the reaction must be replaced.
C.
Forming the activated complex requires energy.
D.
The products have more potential energy than the activated complex.
E.
The reactants have less potential energy than the products.

Answer 1

Answer: C. Forming the activated complex requires energy.

Explanation:

Activation energy is the extra energy that must be supplied to reactants in order to cross the energy barrier and thus convert to products.

In order that reactants change into products, they have to cross an energy barrier. When reactant molecules absorb energy, their bonds are loosened and new loose bonds are formed between them.

The intermediate thus formed is called as activation complex. It is unstable and immediately dissociates to form stable products by release of energy.