Question

Dumas and Kjeldahl's methods are used for thequantitative estimation of_____________.

• A. C and H
• B. Halogens, S, and P
• C. N
• D. All

Answer 1

The correct option is C N

Nitrogen can be estimated by either of the two methods:
Dumas' method
Kjeldahl's method

Kjeldahl's method is a faster method than Dumas' method. However, this method is used only for those organic compounds that are converted quantitatively to ammonium sulphate on heating strongly with concentrated sulphuric acid.

Kjeldahl's method cannot be used for the organic compounds,

• Containing nitrogen in the ring, e.g., pyridine, quinoline etc.

• Containing nitro (-$N{O}_2$) and diazo (-N = N-) groups.