Question

Which of the following statements is/are correct?

• A. Aluminium wire is used in Beilstein test
• B. Nitrogen gas is quantitatively estimated in Dumas method
• C. In Kjeldahl's method, organic compound is reacted with conc. $H_{2}S{O}_4.K_{2}S{O}_4$ and $N{a}_{2}S{O}_4$ are also added
• D. All organic compounds contain both C and H

Answer 1

The correct option is B Nitrogen gas is quantitatively estimated in Dumas method

Copper wire is used in Beilstein test.
All organic compounds contain carbon, some of them doesnt have H.

Nitrogen can be estimated by either of the two methods:

• Dumas' method

• Kjeldahl's method

A known mass ($0.3to0.5$ g) of the given organic compound is digested with concentrated $H_{2}S{O}_4$, in presence of a small quantity of potassium sulphate and copper sulphate in a Kjeldahl's flask. Potassium sulphate raises the boiling point of sulphuric acid and copper sulphate catalyzes the digestion. In 3 to 4 hours, the organic compound is completely decomposed to form ammonium sulphate.