29.5 mg of an organic compound containing nitrogen was digested according to Kjeldahl's method and the evolved ammonia was absorbed in 20 mL of 0.1 M HCl solution. The excess of the acid required

Question

29.5 mg of an organic compound containing nitrogen was digested according to Kjeldahl's method and the evolved ammonia was absorbed in 20 mL of 0.1 M 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

TestHub · Accepted Answer

Moles of HCl reacting with ammonia ​ = ( moles of HCl absorbed ) − ( moles of NaOH solution required) = ( 20 × 0.1 × 1 0 − 3 ) − ( 15 × 0.1 × 1 0 − 3 ) = moles of NH 3 ​ evolved. = moles of nitrogen in organic compound ​ ​ ∴ wt. of nitrogen in org. comp = 0.5 × 1 0 − 3 × 14 = 7 × 1 0 − 3 g % wt = 29.5 × 1 0 − 3 7 × 1 0 − 3 ​ = 23.7% ​

Chemistry - PRACTICAL ORGANIC CHEMISTRY Question with Solution | TestHub

Options:

Doubts & Discussion