The `pH` of `0.1 M` solution of the following salts increases in the order

Options

A. `HCI lt NaCI lt NaCN lt NH_(4)CI`
B. `NaCN lt NH_(4)CI lt NaCI lt HCl`
C. `HCI lt NH_(4)CI lt NaCI lt NaCN`
D. `NaCI lt NH_(4)CI lt NaCN lt HCI`

Answer

C

Explanation

The aqueous solution of NaCI is neutral `(pH=7)` as it does not undergo hydrolysis. The aqueous solution of NaCN is basic `(pHgt7)` on account of anionic hydrolysis: `CN^(-)+H_(2)OhArrHCN+OH^(-)`
The aqueous solution of `NH_(4)Cl` is slightly acidic due to cationic hydrolysis:
`NH_(4)^(+)(aq.)+H_(2)O(l)hArr NH_(4)OH+H^(+)(aq.)`
The aqueous solution of HCl (a strong acid) has the lowest pH value.