The correct order of reactivity for reactions involving cleavage of $\mathrm{C}-\mathrm{X}$ bond in…
The correct order of reactivity for reactions involving cleavage of $\mathrm{C}-\mathrm{X}$ bond in following compounds is
I>III>II
III>II>I
I>II>III
II>III>I
Solution
Cleavage of $\mathrm{C}-\mathrm{X}$ bond occurred by $\mathrm{Ar}-\mathrm{SN}$ reaction.
Rate of $\mathrm{Ar}-\mathrm{SN} \propto-\mathrm{M},-\mathrm{I} \propto \frac{1}{+\mathrm{M}+\mathrm{I}}$