Which among the following salts turns red litmus blue in its aqueous solution?

The $pH$ of an aqueous solution of $CH_3COONH_4$ is found to be $6.7$ at $25\,^{\circ}C$. The concentration of the $CH_3COONH_4$ solution is ($K_a$ for $CH_3COOH = 1.0 \times 10^{-5}$ and $pK_b$ for $NH_4OH = 4.4$)

What is the $pH$ of a $K_2S$ solution?

The $pH$ of an aqueous solution of $CH_3COONa$ of concentration $C \ M$ is given by:

The approximate $pH$ of $0.01 \ M \ NaHA$ is calculated by: ($K_{a_1} = 10^{-6}$ and $K_{a_2} = 10^{-8}$ are ionization constants of $H_2A$)

In the hydrolysis of a salt of a weak acid and a strong base,$A^{-} + H_{2}O \rightleftharpoons HA + OH^{-}$,the hydrolysis constant $(K_{h})$ is equal to...