NEET2026ChemistryChapterActual
During the qualitative analysis of an inorganic salt, the addition of dilute HCl produces a colourless gas with a highly offensive smell resembling rotten eggs. Furthermore, this gas turns a filter paper moistened with lead acetate solution black. Identify the anion present in the salt.
Options
- ASulphite, SO ₃²⁻
- BSulphide, S ²⁻
- CNitrite, NO ₂⁻
- DChloride, Cl ⁻
Correct answer
B. Sulphide, S ²⁻
Step-by-step solution
When dilute HCl is added to a salt containing a sulphide ion ( S ²⁻ ), hydrogen sulphide ( H ₂ S ) gas is evolved. S ²⁻ + 2 H ⁺ H ₂ S Hydrogen sulphide is a colourless gas with a characteristic rotten egg smell. When it comes in contact with lead acetate, it forms a black precipitate of lead sulphide ( PbS ). H ₂ S + Pb ( CH ₃ COO )₂ PbS + 2 CH ₃ COOH Thus, the anion present in the salt is sulphide ( S ²⁻ ). Answer: Sulphide, S ²⁻