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

Calculate the percentage hydrolysis of $NaOCN$ in its $0.003 \ M$ aqueous solution ($K_a$ for $HOCN = 3.33 \times 10^{-4} \ M$) .....$\%$

If the dissociation constant of $HCN$ is $1.3 \times 10^{-9}$ and $K_w = 1 \times 10^{-14}$,then the $pH$ and percentage of hydrolysis of $\frac{N}{100} \ KCN$ are respectively:

Which one of the following salts gives an acidic solution in water?

An aqueous solution of sodium carbonate has a $pH$ greater than $7$ because

$A$ white substance having alkaline nature in solution is