Q. In the Kjeldahl's method for estimation of nitrogen present in a soil sample, ammonia evolved from 0.75 g sample neutralized 10 mL of 1M $H_2SO_4$. The percentage of nitrogen in the soil is :
A) 37.33
B) 45.33
C) 35.33
D) 43.33
Explanation
[Solution] 10 mL of 1 M $H_2SO_4$ neutralises 20 mmol $NH_3$ = 0.28 g N; % N = $\frac{0.28}{0.75} \times 100 = 37.33$. Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.