Benzaldehyde reacts with ammonia in the ratio 3:2 with loss of water to form hydrobenzamide (C6H5CH=N)2CHC6H5. Taking C 12, H 1, N 14, its molar mass in g/mol is

JEE Advanced levelSingle correct optionDifficulty 3 of 3co050

Benzaldehyde reacts with ammonia in the ratio 3:2 with loss of water to form hydrobenzamide $(C X_{6} H X_{5} CH = N) X_{2} CHC X_{6} H X_{5}$ . Taking C 12, H 1, N 14, its molar mass in g/mol is

3 C X_{6} H X_{5} CHO + 2 NH X_{3} - > C X_{21} H X_{18} N X_{2} + 3 H X_{2} O

. The molar mass is

21 \times 12 + 18 \times 1 + 2 \times 14 = 298

. The value 316 would include one retained water, and 280 would include one extra water lost.