The correct difference between first and second order reactions is that

Options

A. the rate of a first-order reaction does not depend on reactant concentrations, the rate of a second-order reaction does depend on reactant concentrations
B. the half-life of a first-order reaction does not depend on `[A]_0`, the half-life of a second-order reaction does depend on `[A]_0`
C. a first-order reaction can be catalysed, a second order reaction cannot be catalysed
D. the rate of a first-order reaction does depend on reactant concentrations, the rate of a second-order reaction does not depend on reactant concentrations.

Answer

B

Explanation

For a first order reaction, `t_(1//2)=(0.693)/(k)`
which is independent of initial concentration `[A]_0`.
For second order reaction, `t_(1//2)=(1)/(k[A]_0)`
Half life depends on initial concentration of reactant.