In the Kjeldahl's method for estimation of nitrogen present in a soil sample, ammonia evolved from 0.75 g of sample neutralized 10 mL of 1 M H2SO4. The percentage of nitrogen in the soil is :

Question

In the Kjeldahl's method for estimation of nitrogen present in a soil sample, ammonia evolved from 0.75 g of sample neutralized 10 mL of 1 M H2SO4. The percentage of nitrogen in the soil is : (A) 37.33 (B) 45.33 (C) 35.33 (D) 43.33

Tardigrade Admin · Accepted Answer

∵ M × V(m l)=m mol 10 m mol H 2 SO 4=20 m mol of NH 3 [ H 2 SO 4+2 NH 3 longrightarrow( NH 4)2 SO 4] 1 mol NH 3 contains 14 g nitrogen 20 × 10-3 mol NH 3 contains 14 × 20 × 10-3 nitrogen 0.75 g of sample contains % Nitrogen =(14 × 20 × 10-3/0.75) × 100=37.33 %

Q. In the Kjeldahl's method for estimation of nitrogen present in a soil sample, ammonia evolved from 0.75g of sample neutralized 10mL of 1MH2​SO4​. The percentage of nitrogen in the soil is :

37.33

45.33

35.33

43.33

∵M×V(ml)=m mol 10mmolH2​SO4​=20m mol of NH3​ [H2​SO4​+2NH3​⟶(NH4​)2​SO4​] 1molNH3​ contains 14g nitrogen 20×10−3 mol NH3​ contains 14×20×10−3 nitrogen 0.75g of sample contains % Nitrogen =0.7514×20×10−3​×100=37.33%

Q. In the Kjeldahl's method for estimation of nitrogen present in a soil sample, ammonia evolved from $0.75 g$ of sample neutralized $10 m L$ of $1 M H_{2} S O_{4}$ . The percentage of nitrogen in the soil is :