The aqueous solution of which one of the following is basic?

Which of the following produce an alkaline solution when dissolved in water?
$(i)$ Borax
$(ii)$ Potash alum
$(iii)$ $Na_2CO_3$
$(iv)$ $NH_4NO_3$

Find out $K_a$ for the acid when the degree of hydrolysis of $0.1 \ M \ CH_3COONa$ is $1 \ \%$.

Which of the following salts does not undergo hydrolysis in water?

The degree of hydrolysis in hydrolytic equilibrium $A^{-} + H_2O \rightleftharpoons HA + OH^{-}$ at salt concentration of $0.001 \ M$ is $(K_a = 1 \times 10^{-5})$

The $pK_a$ of a weak acid $(HA)$ and $pK_b$ of a weak base $(BOH)$ are $3.2$ and $3.4$ respectively. Find the $pH$ of their salt $(AB)$.