`H_(2)S` can form

Options

A. four series of salt
B. two series of salt
C. only one series of salts
D. three series of salt

Answer

2

Explanation

Hydrogen sulphide has no effect on dry litmus paper but once the litmus paper becomes wet it will turn blue litmus paper a wine-red colour, showing that it functions as a weak acid in solution.
`H_(2)S` is very weak dibasic acid.It ionization in water takes place in two stages, the second one occuring only to a very minute extent:
`H_(2)S(aq.)+H_(2)O(l) hArr H_(3)O^(+)(aq.)+HS^(-)(aq.)`
`HS^(-)(aq.)+H_(2)O(l) hArr H_(2)O^(+))aq.)+S^(2-)(aq.)`
In the presence of hydroxyl ions (a much stronger proton acceptor than water molecules ,the ionisation of hydrogen sulphide is much more extensive.
Most metal sulphides can be regarded as salts of `H_(2)S`. Since it is dibasic two series of salts can be drived from it .The hydrogen sulphides and normal sulphides (or just sulphides). For example ,the reaction with sodium hydroxide solution produces the hydrogen sulphide and sulphide,i.e.,`Na^(+)HS^(-)` and`(Na^(+))_(2)S^(2-)`
`H_(2)S(aq.)+Na^(+)OH^(-)(aq.)rarrNa^(+)HS^(-)(aq.)+H_(2)O(l)`
`Na^(+)Hs^(-)(aq.)+Na^(+)OH^(-)(aq.)rarr(Na^(+))_(2)S^(2-)(aq.)+H_(2)O(l)`
The reaction do not go to completion, i.e, the alkali metal hydrosulphides and sulphides show an alkaline reaction in solution.thsu demonstrating presence of `OH^(-)(aq.)` ions.