Question

Which of the following alkyl halides is hydrolysed by $S_{N}1$ mechanism most easily?

• A. $$C{H}_{3}Cl$$
• B. $$C{H}_{3}C{H}_{2}Cl$$
• C.
  $$C{H}_{3}C{H}_{2}C{H}_{2}Cl$$
• D. $$(C{H}_3{)}_{3}CCl$$

Answer 1

The correct option is D $$(C{H}_3{)}_{3}CCl$$

$S_{N}1$ mechanism follows formation of carbocation.
Reactivity is directly propotional to the stability of carbocation formed from alkyl halide. As we know,
$3^0$ carbocation $>2^0$ carbocation $>1^0$ carbocation (order of stability). In option (d), tertiary carbocation will be formed. Therefore, option (d) will undergo $S_{N}1$ mechanism.