An aqueous solution of chloroacetic acid of strength 0.2 `mol*L^(-1)` has pH 1.7. calculate the degree of dissociation of the acid.

Explanation

Chloroacetic acid is a weak monobasic acid. In aqueous solution of such an acid, `[H_(3)O^(+)]=alphac`, where `alpha=`degree of ionisation of the acid in solution and c=molar concentration of the solution.
For the solution, `pH=1.7`. Hence, in the solution, `[H_(3)O^(+)]=10^(-pH)=10^(-1.7)=0.02(M)`
`therefore alpha c=0.20 or, alpha=(0.02)/(0.2)=0.1`
`therefore `Degree of ionisation of the acid=10%