The ionisation cosntabnt of an acid, `K_(a)` is the meaure of strength of an acid. The `K_(a)` values of acetic acid, hypochlorous acid and formic acid are `1.74xx10^(-5)`, `3.0xx10^(-8)` and `1.8xx10^(-4)` respectively. Which of the following orders of ph of `0.1` mol `dm^(-3)` solutions of these acids is correct ?

Options

A. acetic acid `gt` hypochlorous acid `gt ` formic acid
B. hypochlorous acid `gt ` acetic acid `gt ` formic acid
C. formic acid `gt` hypochlorous acid `gt `acetic acid
D. fromic acid `gt` acetic acid `gt ` hypochlorous acid

Answer

D

Explanation

Greater the ionization constant, greater is the strength of the acid. Hence,
`{:(,HCO OH ,gt,CH_(3)CO OH,gt,HClO),(K_(a),1.8xx10^(_4),,1.74xx10^(-5),,3.0xx10^(-8).):}`