Question

There is an overall $29$-fold difference in reactivity of $1$-chlorohexane, $2$-chlorohexane towards potassium iodide in acetone. which one is the most reactive and why?

• A. $2$-chlorohexane because it follows $S_{N}1$ path
• B. $2$-chlorohexane because it follows $S_{N}2$ path
• C. $1$-chlorohexane because it follows $S_{N}1$ path
• D. $1$-chlorohexane because it follows $S_{N}2$ path

Answer 1

The correct option is D $1$-chlorohexane because it follows $S_{N}2$ path

There is an overall $29$-fold difference in reactivity of $1$-chlorohexane, $2$-chlorohexane towards potassium iodide in acetone. $1$-chlorohexane is the most reactive because it follows $S_{N}2$ path.

Primary alkyl halides undergo substitution by $S_{N}2$ path. The rate of $S_{N}2$ reaction is controlled by steric factors and the rate of $S_{N}2$ reaction is controlled by electronic factors. Primary alkyl halides undergo $S_{N}2$ reaction and since they are sterically least hindered, they are most reactive.

Option D is correct.