JEE Chemistry 2023 Question with Solution

Given: We need to identify the compound that gives a positive Lassaigne's test for both nitrogen and halogen.

Find: Which option contains the required features for detection in Lassaigne's test.

Lassaigne's test detects nitrogen, sulfur, and halogens in organic compounds. On sodium fusion, nitrogen is converted to $\mathrm{NaCN}$ and halogen is converted to $\mathrm{NaX}$ where $\mathrm{X = Cl, Br, I}$.

Checking the options from the provided solution:

1. $\mathrm{N_2H_4\cdot HCl}$: Contains nitrogen but no halogen.
2. $\mathrm{CH_3NH_2\cdot HCl}$: Contains both nitrogen and halogen.
3. $\mathrm{NH_4Cl}$: Contains nitrogen and halogen but is not an organic compound.
4. $\mathrm{NH_2OH\cdot HCl}$: Contains nitrogen and halogen but does not form the required products in Lassaigne's test.

Therefore, only $\mathrm{CH_3NH_2\cdot HCl}$ gives a positive Lassaigne's test for both nitrogen and halogen.

The solution concludes the compound is option (2), which corresponds to B, but the page also shows "The Correct Option is A". Based on the worked conclusion and final answer line, the defensible answer is B.