Question

The compound that does not give a positive test for nitrogen in Lassaigne’s test is

• A.
• B.
• C.
• D.

Hint:

For Lassaigne’s test, nitrogen must be directly bonded to carbon in the organic com pound for a positive test.

Answer 1

The Correct Option is B

In Lassaigne’s test, nitrogen-containing compounds react with sodium fusion extract to produce a distinctive blue or purple color when treated with sodium picrate or similar reagents. Compounds lacking nitrogen will not yield a positive test result.

The provided compounds are:

• (A) Nitrophenol (C₆H₄NO₂OH) contains nitrogen, resulting in a positive test.
• (B) Chlorobenzene (C₆H₅Cl) lacks nitrogen and will not give a positive test in Lassaigne’s test.
• (C) Aniline (C₆H₄NH₂) contains nitrogen and will produce a positive test.
• (D) Aminobenzene (C₆H₄NH₂) contains nitrogen, leading to a positive test.

Therefore, the compound that does not exhibit a positive nitrogen test is (B) Chlorobenzene.