Question

Choose the halogen which is most reactive towards SN₁ reaction in the given compounds (A, B, C & D)

(1) A-Br_(b) ; B-I_(b) ; C-Br_(b) ; D-Br_(b) 

(2) A-Br_(a) ; B-I_(a) ; C-Br_(b) ; D-Br_(a) 

(3) A-Br_(b) ; B-I_(a) ; C-Br_(a) ; D-Br_(a) 

(4) A-Br_(b) ; B-I_(a) ; C-Br_(a) ; D-Br_(a)

Answer 1

(2) A-Br_(a) ; B-I_(a) ; C-Br_(b) ; D-Br_(a) 

Stable is the carbocation, faster will be rate of SN₁ reaction