The dissociation coustant of `H_(2)O, H _(2)Se and H_(2)` Te are `1.8 xx 10 ^(-16) , 1.4 xx 10 ^(-7) , 1.3 xx 10 ^(-4)and 2.2 xx 10 ^(-3),` respectively. What do these values denote ?

Explanation

Dissociation of hydride is given as, `H_(2)MhArr H^(+)+MH^(-)`
For this dissociation equilibrium, a lower value of `K_(a)` denotes that the acid is weak. As the `K_(a)` values increase from `H_(2)O` to `H_(2) Te`, their acidic strength also increases. `H_(2)Te` is retalively a stronger acid. The `K_(a)` values also denote that `OH^(-)` is a stronger base and `TeH^(-)` is a weaker base.