Yellow ammonium sulphide is obtained by passing `H_(2)S` into

Options

A. `(NH_(4))_(2)CO_(3)`
B. a mixture of `NaOH` and `NH_(3)`
C. `NH_(3)`
D. a mixture of `NH_(3)` and `NH_(4)Cl`

Answer

3

Explanation

If a dilute solution of ammonia is saturated with `H_(2)S` then ammonium hydrogen Sulphide `NH_(4)HS` is formed, not `(NH_(4))_(2)S` . The latter exists onlyt at low temperatures in the absence of water, solution of `NH_(4)HS` are colourless, and when mixed with an equimolar amount of `NH_(3)` it is used as a laboratory reagent.
More commonly 'yellow ammonium sulphide' is used as a labortory reagent to precipitate metal sulohides in qualitarive analysis. Yellow ammonium sulphide is really a mixture of ammonium polysulphides, and is made by dissolving sulphur in colourless `NH_(4)HS//NH_(3)` solution.