Question

Higher order (> 3) reactions are rare due to ______.

Options

• low probability of simultaneous collision of all the reacting species.

• increase in entropy and activation energy as more molecules are involved.

• shifting of equilibrium towards reactants due to elastic collisions.

• loss of active species on collision.

Answer 1

Higher order (> 3) reactions are rare due to low probability of simultaneous collision of all the reacting species.

Explanation:

Order of reaction refers to the number of reactant species involved in the rate-determining step. For a reaction to be of fourth order or higher, 4 or more molecules would need to collide simultaneously in the correct orientation and with sufficient energy. The probability of such a collision occurring decreases drastically as the number of molecules increases. Hence, the reactions of order higher than 3 are very rare in practice.