Kjeldahl's Method
Kjeldahl's method cannot be used for nitrogen estimation in:
Select the correct option:
Solution
Nitro compounds
Kjeldahl's Method is widely used but has significant limitations.
- Inability: It cannot be used for organic compounds where nitrogen is part of a Nitro group (−NO2), Azo group (−N=N−), or present in a ring (like Pyridine).
- Reason: In these compounds, nitrogen does not quantitatively convert into ammonium sulfate when heated with concentrated sulfuric acid. Instead, most of the nitrogen escapes as N2 gas during the digestion process, leading to inaccurate (too low) results.
🔒 Solution Hidden from View
Submit your answer to unlock the detailed step-by-step solution.
More kjeldahl's method Practice Questions
In Kjeldahl's method, 0.30 g of an organic compound liberated ammonia that exactly neutralised 30 mL...
In Kjeldahl's method, 0.30 g of an organic compound liberated ammonia that exactly neutralised 30 mL...
Kjeldahl's method gives accurate nitrogen estimation for many compounds but fails for certain classe...
Kjeldahl's method gives accurate nitrogen estimation for many compounds but fails for certain classe...
In Kjeldahl's estimation, 1.4 g of an organic compound liberated ammonia that was exactly neutralise...
In Kjeldahl's estimation, 1.4 g of an organic compound liberated ammonia that was exactly neutralise...
About This Question
- Subject
- chemistry
- Chapter
- purification and characterisation of organic compounds
- Topic
- kjeldahl's method
- Difficulty
- Medium
- Year
- 2025
Solution
Correct Answer:
Nitro compounds
Kjeldahl's Method is widely used but has significant limitations.
- Inability: It cannot be used for organic compounds where nitrogen is part of a Nitro group (−NO2), Azo group (−N=N−), or present in a ring (like Pyridine).
- Reason: In these compounds, nitrogen does not quantitatively convert into ammonium sulfate when heated with concentrated sulfuric acid. Instead, most of the nitrogen escapes as N2 gas during the digestion process, leading to inaccurate (too low) results.
This medium difficulty chemistry question is from the chapter purification and characterisation of organic compounds, covering the topic of kjeldahl's method. It appeared in the 2025 exam.
Looking for more practice? Explore all chemistry questions or browse purification and characterisation of organic compounds questions on RankGuru.