Question

Which of the following is/are true regarding nucleophilic substitution reaction?

• A. Reactivities in an $S_{N}2$ reaction
  
• B. $S_{N}1$ reaction is favoured by polar protic solvent
• C. Nucleophilicity affects the rate of $S_{N}2$ reaction
• D. Reactivities in an $S_{N}1$ reaction:$R–I>R–Br>R–Cl>R–F$.

Answer 1

Answer: (A), (B), (C), (D)

The correct options are
A Reactivities in an $S_{N}2$ reaction

B $S_{N}1$ reaction is favoured by polar protic solvent
C Nucleophilicity affects the rate of $S_{N}2$ reaction
D Reactivities in an $S_{N}1$ reaction:$R–I>R–Br>R–Cl>R–F$.

As the steric hindrance increases rate of $S_{N}2$ reaction decreases. Polar protic solvents favour $S_{N}1$ reaction.