The solution of sodium carbonate has $pH$

The aqueous solution of copper $(II)$ sulphate is slowly hydrolysed forming basic copper sulphate whose chemical composition is

The degree of hydrolysis of a $N/100$ $KCN$ solution is = ....... (Given $K_a = 1.4 \times 10^{-9}$)

When a $0.1 \, M$ acetic acid solution is titrated with a $0.1 \, M$ $NaOH$ solution,calculate the $pH$ at the equivalence point ($K_a$ for acetic acid = $1.9 \times 10^{-5}$).

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 $(AB)$.

What will be the $pH$ and $\alpha$ (degree of hydrolysis) respectively for the salt $BA$ of $0.1 \ M$ concentration? (Given: $K_a$ for $HA = 10^{-6}$ and $K_b$ for $BOH = 10^{-6}$)