In the second group of qualitative analysis, `H_(2)S` is pass through a solution acidified with HCl in order to :

Options

A. limit the concentration of `S^(2-)` ions
B. increase the solubility of `H_(2)S`
C. increase the concentration of `S^(2-)` ions
D. provide extra `Cl^(-)` ions

Answer

A

Explanation

HCl suppresses the concentration of `S^(2-)` ions in solution due to common ion effect.
`H_(2)S overset((aq))hArr 2H^(+) (aq) + S^(2-) (aq)`
`HCl overset((aq))rarr H^(+) (aq) + Cl^(-) (aq)`