Question

Which of the following alkyl halides will undergo SN1
reaction most readily?
(a) (CH₃ )₃ C — F (b) (CH₃ )₃ C — Cl
(c) (CH₃ )₃ C — Br (d) (CH₃ )₃ C — I

Answer 1

Which of the following alkyl halides will undergo SN1

reaction most readily?

(a) (CH₃ )₃ C — F (b) (CH₃ )₃ C — Cl

(c) (CH₃ )₃ C — Br (d) (CH₃ )₃ C — I

- All of the given options are tertiary alkyl halides

- In SN1 reactions, the alkyl halides needs to be ionized

- So the alkyl halide which will be most stabilised after ionization will react the fastest

- Out of these alkyl halides, (CH₃ )₃ C — I gets most stabilised after ionisation due to  the large size of iodine ion because the negative charge gets delocalised to a much larger area as compared to the other alkyl halides

- So the correct option is (d) (CH₃ )₃ C — I