Question

Which of the following is the correct order of decreasing $S_{N}2$ reactivity?

• A. $R{CH}_{2}X>R_{3}CX>R_{2}CHX$
• B. $R{CH}_{2}X>R_{2}CHX>R_{3}CX$
• C. $R_{3}CX>R_{2}CHX>R{CH}_{2}X$
• D. $R_{2}CHX>R_{3}CX>R{CH}_{2}X$

Answer 1

The correct option is B $R{CH}_{2}X>R_{2}CHX>R_{3}CX$

As the number of $R$ groups on carbon with leaving group increases, rate of $S{N}^2$ reaction decreases.

$RC{H}_{2}X>R_{2}CHX>R_{3}CX$ .