At a certain temperature, the ionisation constannt of three weak acids HA, HB and HC are `4.0xx10^(-5),5.2xx10^(-4) and 8.6xx10^(-3)`, respectively. If the molar concentrations of their solutions are the same, then arrange them in order of their increasing strength.

Explanation

The larger the ionisation constant `(K_(a))` of an acid, the greater the extent to which it undergoes ionisation in its aqueous solution, and hence the higher the concentration of `H_(3)O^(+)` ions produced by it in the solution. Alternatively, the larger the value of `K_(a),` of an acid, the greater is its strength. the increasing order of the given acid with respect to their `K_(a):HA lt HB lt HC`. Consequently, the order of the given acid in terms of increasing strength in their aqueous solutions will be `HA lt HB lt HC`.