Question

11.
0.2 gm. Of an organic compound
was analysed by KJeldahl's method.
Ammonia evolved was absorbed in
60 mL N/5 H.SO. Un used acid
required 40 ml of N/10 NaOH for
complete neutralisation. The
percentage of nitrogen in the
compound is-
a) 36%
c) 56%
87%
d) 69%
​

Answer 1

Answer:

Mass of organic compound = 0.2gm

unused acid required = 40ml*N/10 NaOH

40mlN/10 NaOH = 40mlN/10 N+H2so4

= 20mlN/5 N2so4

Acid used for absorption of ammonia = ( 60 - 20 )mlH2so4

40ml N/5 H2so4

% of nitrogen = 1.4 × N × V/W

= 1.4 × 1/5 × 40/0.2

= 56%