The `pK_(a)` of a weak acid, `HA`, is `4.80`. The `pK_(b)` of a weak base, `BOH`, is `4.78`. The `pH` of an aqueous solution of the corresponding salt, `BA`, will be:

Options

A. 8.58
B. 4.79
C. 7.01
D. 9.22

Answer

C

Explanation

In aqueous solution, BA(salt) hydrolyses to give
`BA + H_(2)O to underset("base")(BOH) + underset("acid")(HA)`
Now pH since by
`pH=1/2 pK_(w) + ½ pK_(a) -1/2 pK_(b)`
Substituting the given values, we get =`pH=1/2(1.4+4.80-4.78)= 7.01`