Benzamide (C6H5CONH2) of mass 12.1 g is subjected to Hofmann bromamide degradation with Br2 + NaOH and gives aniline in 80% yield. Using atomic masses H = 1, C = 12, N = 14, O = 16, calculate the mass of aniline obtained in grams (two decimal places).

JEE Main levelNumerical answerDifficulty 2 of 3nc176

Benzamide ( $C X_{6} H X_{5} CONH X_{2}$ ) of mass $12.1 g$ is subjected to Hofmann bromamide degradation with $Br X_{2} + NaOH$ and gives aniline in $80%$ yield. Using atomic masses H = 1, C = 12, N = 14, O = 16, calculate the mass of aniline obtained in grams (two decimal places).

Numerical answer type, tolerance 0.03.

Molar mass of benzamide

= 7 (12) + 7 (1) + 14 + 16 = 121 g mo l^{- 1}

, so

n = 12.1/121 = 0.100

mol. One mole of amide gives one mole of aniline (

C X_{6} H X_{5} NH X_{2}

93 g mo l^{- 1}

). Theoretical mass

= 0.100 \times 93 = 9.30

g; at

80%

yield mass

= 7.44