In the estimation of nitrogen by Kjeldahl's method, 2.8 gm of an organic compound required 20 millimole of H 2 SO 4 for the complete neutralisation of NH 3 gas evolved. The percentage of nitrogen in the sample is:

Question

In the estimation of nitrogen by Kjeldahl's method, 2.8 gm of an organic compound required 20 millimole of H 2 SO 4 for the complete neutralisation of NH 3 gas evolved. The percentage of nitrogen in the sample is: (A) 20 % (B) 10 % (C) 40 % (D) 30 %

Tardigrade Admin · Accepted Answer

Percentage of N =(1.4 × mEq ⋅ text of H 2 SO 4 text used to neutralise NH 3/ text Weight of compound ) m moles of H 2 SO 4=20 mEq. of H 2 SO 4=20 × 2=40 Percentage of N =(1.4 × 40/2.8)=20 %

Q. In the estimation of nitrogen by Kjeldahl's method, $2.8 g m$ of an organic compound required $20$ millimole of $H_{2} S O_{4}$ for the complete neutralisation of $N H_{3}$ gas evolved. The percentage of nitrogen in the sample is:

$20%$

$10%$

$40%$

$30%$

Percentage of $N$
$= \frac{1.4 \times m Eq \cdot of H _{2} S O _{4} used to neutralise N H _{3}}{Weight of compound}$
$m$ moles of $H_{2} S O_{4} = 20$
mEq. of $H_{2} S O_{4} = 20 \times 2 = 40$
Percentage of $N = \frac{1.4 \times 40}{2.8} = 20%$

Q. In the estimation of nitrogen by Kjeldahl's method, 2.8gm of an organic compound required 20 millimole of H2​SO4​ for the complete neutralisation of NH3​ gas evolved. The percentage of nitrogen in the sample is:

20%

10%

40%

30%