Kjeldahl's method cannot be used for the estimation of nitrogen in which compound?
Kjeldahl's method cannot be used for the estimation of nitrogen in which compound?
Show Hint
Nitro compounds
Azo compounds
Nitrogen in rings (sometimes)
Works well for amines, amides, proteins.
- Option a
- Option b
- Option c
- Option d
The Correct Option is C
Solution and Explanation
Kjeldahl method estimates nitrogen by converting it into ammonium sulfate during digestion.
It fails for compounds where nitrogen:
Is present in azo group (–N=N–)
Is in nitro (–NO\(_2\)) or certain heterocycles
Step 1: Analyze options
Amides: Kjeldahl works
Amino acids: Kjeldahl works
Azobenzene: contains azo (–N=N–)
Amino acids (D): measurable
Conclusion:
Azo compounds are not estimated by Kjeldahl method.
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