The aqueous solution of $CuSO_4$ is

Which of the following aqueous solutions will have the highest $pH$?

Find the equilibrium constant for the equilibrium reaction:
$HCOO^{-} + H_2O \rightleftharpoons HCOOH + OH^{-}$
Given that the dissociation constant of formic acid is $K_a(HCOOH) = 1.8 \times 10^{-4}$.

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 $H_2A$)

Calculate the percentage of hydrolysis in $0.01 \ M$ aqueous solution of $NaOCN$ ($K_b$ for $OCN^{-} = 10^{-10}$)

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 $(AB)$.