When the concentration of alkyl halide is tripled and the concentration of $\mathrm{O}\stackrel{⊝}{\mathrm{H}}$ ion is reduced to half, the rate of ${\mathrm{S}}_{\mathrm{N}}2$ reaction increases by:

The reaction given is an example of:

In the following reaction the most probable product will be:

What is the final product of the given reaction?

In ${\mathrm{S}}_{\mathrm{N}}2$ substitution reaction :-

$\mathrm{R}-\mathrm{Br}+\mathrm{Nal}\stackrel{\mathrm{Acetone}}{\to }\mathrm{R}-\mathrm{l}+\mathrm{NaBr}$

Which one of the following has the highest relative rate?