Kjeldahl method for estimation of nitrogen in inorganic organic compound?

Answer 1

This is a very convenient method but its use is restricted.This method is suitable for estimating nitrogen in those organic compounds in which nitrogen is linked to carbon and hydrogen. The method is not used in the case of nitro, azo and azoxy compounds. The method is extensively used for estimated nitrogen in food, fertilizers and agricultural products.

Principle:- the method is based on the fact that when the nitrogenous compound is heated with concentrated sulphuric acid in presence of copper sulphate, the nitrogen present in the compound is quantitatively converted to ammonium sulphate. The ammonium sulphate so formed is decomposed with excess of alkali and the ammonia evolved is estimated volumetrically. The percentage of nitrogen is then calculated from the amount of ammonia.

Answer 2

By this method organic compound containing nitrogen is worked with conc. sulphuric acid which converts the nitrogen into Ammonia the ammonia thus produced isestimated by titration with standard acid and finally nitrogen is estimated.

Answer 3

The Kjeldahl method is a widely used technique for determining the nitrogen content in organic compounds. It involves digesting the sample with concentrated sulfuric acid, which converts the nitrogen to ammonium sulfate. The ammonia is then distilled and collected in a solution of known acid, and the amount of nitrogen is determined by titration.