29.5 mg of an organic compound containing nitrogen was digested according to Kjeldahl's method and the evolved ammonia was absorbed in 20mL of 0.1M HCL solution. The excess of the acid required 15 mL of 0.1 M NaOH solution for complete neutralization. The percentage of nitrogen in the compound is:

Options

A. 29.5
B. `59.0`
C. 47.4
D. 23.7

Answer

D

Explanation

Weight of substance taken `= 29.5 xx 10^(-3) g`
Volume of acid taken 20 mL of 0.1 N HCl
`:.` Volume of acid used = 20 - 15 = 5 mL of 0.1 N HCl
`%N = (1.4 xx "Volume" xx "Normality")/("Weight of substance taken") = (1.4 xx 5 xx 0.1)/(29.5 xx 10^(-3))`
`= 23.73`