Which one of the following salts gives an aqueous solution which is weakly basic?

The $pH$ of ammonium phosphate solution,if $pK_a$ of phosphoric acid and $pK_b$ of ammonium hydroxide are $5.23$ and $4.75$ respectively,is ..... .

The degree of hydrolysis of a salt of weak acid and weak base in its $0.1 \, M$ solution is found to be $50 \%$. If the molarity of the solution is $0.2 \, M$,the percentage hydrolysis of the salt should be $...... \%$.

An aqueous solution of aluminium sulphate would show

Which of the following salts undergoes anionic hydrolysis?

The $pK_a$ of a weak acid,benzoic acid and $pK_b$ of a weak base,ammonium hydroxide are $4.25$ and $4.75$ respectively. Then the $pH$ of $0.1 \ M$ solution of ammonium benzoate will be