Diazonium salt decomposes as
`C_(6)H_(5)N_(2)^(+)Cl^(-) rarr C_(6)H_(5)Cl + N_(2)`. At `0^(@)C`, the evolution of `N_(2)` becomes two times faster when the initial concentration of the salt is doubled. Therefore, it is

Options

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

A

Explanation

For a rection `C_(6)H_(5)N_(2)^(+)Cl^(-) rarr C_(6)H_(5)Cl + N_(2)`
Let the rate law be
`r = (d[N_(2)])/(d t) = k[C_(6)H_(5)N_(2)^(+)Cl^(-)]^(x)`
`= k["Salt"]^(x)` …(i)
From given, if `2r = (2d[N_(2)])/(d t) = k(2["salt"])^(x)` …(ii)
Then, on dividing (i) by (ii), we get
`(1)/(2) = ((1)/(2))^(x) rArr x = 1`
`:.` Reaction is of Ist order.