Question

The order of reactivities of the following alkyl halides for a $S_{N}2$ reaction is:

• A. $RF>RCl>RBr>RI$
• B. $RF>RBr>RCl>RI$
• C. $RCl>RBr>RF>RI$
• D. $RI>RBr>RCl>RF$

Answer 1

The correct option is D $RI>RBr>RCl>RF$

If alkyl groups are same, the order of leaving ability of halides in $S_{N}2$ reaction is $RI>RBr>RCl>RF$.