Consider the following sequence of reactions to produce major product (A) \beginaligned & Molar mass of product (A) is g ~mol^-1 . & (Given molar mass in g ~mol^-1 of C: 12, H: 1, O: 16, Br: 80, ~N: 14, P: 31 ) \endaligned

Compounds Containing Nitrogen PYQ — JEE Main 2025 · 23 Jan · Shift 1 · Q24 with Solution

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Correct answer: 171

Identify the reaction sequence

This is the standard conversion:
$\text{amide} \xrightarrow{Br_2/NaOH} \text{amine with one carbon less}$
This is the Hofmann bromamide degradation reaction.
General result of Hofmann bromamide reaction

If the starting compound is:
$RCONH_2$
then the major product is:
$RNH_2$
That is, the carbonyl carbon is lost, and a primary amine containing one carbon less is formed.
Determine product (A)

From the given reaction scheme, the amide corresponds to benzamide:
$C_6H_5CONH_2$
On Hofmann bromamide degradation:
$C_6H_5CONH_2 \xrightarrow{Br_2/NaOH} C_6H_5NH_2$
So product $(A)$ is aniline.
Calculate molar mass of aniline

Molecular formula of aniline:
$C_6H_5NH_2 = C_6H_7N$
Molar mass:
$= 6(12) + 7(1) + 14$ $= 72 + 7 + 14 = 93$
Final answer
$\boxed{93}$
Comparison with stored correct answer

Stored correct answer is 171, but the Hofmann bromamide product from benzamide is aniline, whose molar mass is 93 g mol $^{-1}$ .

Hence, I do not agree with the stored answer.