Quantitative analysis of nitrogen

Question

Find the % of nitrogen in an organic compound analysed by kjeldahl method. 1.61g of the compound produced NH_{​​​​​3}​​​​ which  was absorbed in 250 ml of N/2 H_{​​​​​​2}​​​SO4 the remaining acid was then diluted to one litre ,25 ml of which required 25.5 ml of N/10  NaOH for exact neutralisation.

Answer 1

Formula used to calculate % N by Kheldhal's method = 1.4 * M *2 (V-V₁/2)/Mass of organic compound.....2
V= Volume of H₂SO₄ taken = 250ml.
V₁ = volume of NaOH = 25.5ml
M = molarity of H₂SO₄ 
normality H₂SO₄ = 2 x molarity H₂SO₄ 
So molarity will be half of normality of given strength
N/2 H₂SO₄ = M/4 H₂SO₄
Mass of organic compound = 1.61g
Putting the value in formula 2 we get;
% N by Kheldhal's method = 1.4 * 1/4 *2 (250-25.5/2)/1.61= 48.80%

Comments

It is not correct answer