devarshi-dt-logo

Question:

Consider the following reactions:
(i) (CH3)2CH−CH2Br + C2H5OH → (CH3)2CH−CH2OC2H5 + HBr
(ii) (CH3)2CH−CH2Br + C2H5O− → (CH3)2CH−CH2OC2H5 + Br−
The mechanism of reactions (i) and (ii) are respectively:

SN1 and SN2

SN2 and SN2

SN1 and SN1

SN2 and SN1

Solution:

The given reactions are:
(i) (CH3)2CH−CH2Br + C2H5OH → (CH3)2CH−CH2OC2H5 + HBr
(ii) (CH3)2CH−CH2Br + C2H5O− → (CH3)2CH−CH2OC2H5 + Br−
The mechanism of reactions (i) and (ii) are respectively SN1 and SN2.
In the reaction (i), a weak nucleophile, ethanol is used. Hence, it undergoes SN1 substitution.
In the reaction (ii), a strong nucleophile, ethoxide ion is used. Hence, it undergoes SN2 substitution.
Hence, the correct option is A