The ammonia evolved from the treatment of 0.30 g of an organic compound for the estimation of nitrogen was passed in 100 mL of 0.1 M sulphuric acid. The excess of acid required 20 mL of 0.5 M sodium hydroxide solution for complete neutralization. The organic compound is
As we learned,
Law of Definite Proportions -
A compound always contains exactly the same proportion of elements by weight
- wherein
CaCO3 contains 40% Ca, 12% C and 48% O by weight irrespective of the source.
Using kjeldahl process to calculate the % of N in organic compound :
Let unreacted 0.1 M ( = 0.2 N ) H2SO4 = V' ml
, 20 ml of 0.5 M NaOH = V' ml of 0.2 N H2SO4 .
20 x 0.5 = V' x 0.2
V' = 50 ml
used H2SO4 = 100 - 50 ml = 50 ml
% N = 14 N V/W
where N Normality of H2SO4
V Volume of H2SO4 used
% N = 1.4 x 0.5 x 50/ 0.30 = 46.67 %
Urea = NH2 / ONH2 = = 46.67 %