A salt X when dissolved in distilled water gives a clear soltuion which turns red litmus blue. Explain the phenomenon.

Explanation

Basic solution turn red litmus paper . The salt of a weak acid and strong base given a basic solution . So , the given salt X is the salt of a weak acid and a strong base.
Example : When sodium carbonate is dissolved in water, it gets hydrolysed to some extent and forms sodium hydroxide and carbonic acid.
`underset(("Basic salt"))underset("Sodium carbonate")(Na_2CO_(3)(s))+underset("water")(2H_(2)O(l))overset("Hydroysis")hArrunderset(("strong base"))underset("Sodium hydroxide")(2NaOH(aq))+underset("(weak acid)")underset("Carbonic acid")(H_(2)CO_3(aq))`
Being a strong base, sodium hydroxide is fully ionised and gives a large amount of hydroxide ions `(OH^(-))` . Carbonic acid is a weak acid which is only slightly ionised and hence , given a small amount of hydrogen ions `(H^(+))` . The `H^(+)` ions produced by carbonic acid neutralises only a small amount of `OH^(-)` ions produced by sodium hydroxide and the rest amount of `OH^(-)` ions are present in the solution. Hence , the `Na_(2)CO_(3)` solution is basic in nature . It turns red litmus blue.