Statement-1: In the Kjeldahl method for nitrogen estimation, the nitrogen of pyridine cannot be estimated.
Statement-2: The nitrogen in pyridine is part of a homoocyclic ring and does not form ammonium sulfate under the conditions of the Kjeldahl digestion.

Question

Statement-1: In the Kjeldahl method for nitrogen estimation, the nitrogen of pyridine cannot be estimated.

Statement-2: The nitrogen in pyridine is part of a homoocyclic ring and does not form ammonium sulfate under the conditions of the Kjeldahl digestion.

TestHub · Accepted Answer

Statement-1 is true. The Kjeldahl method is not suitable for compounds where nitrogen is directly linked to an aromatic ring (like in nitro compounds, azo compounds) or present in heterocyclic rings (like pyridine, quinoline). This is because such nitrogen does not get quantitatively converted into ammonium sulfate during the digestion with concentrated sulfuric acid.

Statement-2 is incorrect as the ring is heterocyclic.

Chemistry - Mole Concept Question with Solution | TestHub

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