Question

Diazonium salt decomposes as, $C_6{H}_5{N}_2^{+}{Cl}^{-}⟶C_6{H}_{5}Cl+N_2$.
At $0^{o}C$, the evolution of $N_2$ becomes two times faster when the initial concentration of the salt is doubled. Therefore, it is:

• A. a first order reaction
• B. a second order reaction
• C. independent of the initial concentration of the salt
• D. a zero order reaction

Answer 1

The correct option is A a first order reaction

Say,
$v=k{\left[C_6{H}_5{N_2}^{+}{Cl}^{-}\right]}^m$
now,
$\frac{v_f}{v_i}=\frac{k{\left[C_6{H}_5{N_2}^{+}{Cl}^{-}\right]}^m.2^m}{k{\left[C_6{H}_5{N_2}^{+}{Cl}^{-}\right]}^m}=22^m=2m=1$
So it is a first order reaction.