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
(1) 37.33
2NH3 + H2SO4 (NH4)2SO4
Moles of H2SO4 = 10 11000 = 0.01 mol
⇒ moles of NH3 = 2 0.01 = 0.02 mol = moles of N
Mass of N = 0.02 14 = 0.28 g
% N = 0.280.75 100
= 37.33\%
Answer: (1)
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