When $NaCl$ is dissolved in water,the sodium ion is

Which of the following undergoes hydrolysis when dissolved in water?

Calculate the ionic product of the solution formed by mixing equal volumes of $0.004 \, M \, CaSO_4$ and $0.002 \, M \, H_2SO_4$.

The first ionization constant of $H_2S$ is $9.1 \times 10^{-8}$. Calculate the concentration of $HS^{-}$ ion in its $0.1 \ M$ solution. How will this concentration be affected if the solution is $0.1 \ M$ in $HCl$ also? If the second dissociation constant of $H_2S$ is $1.2 \times 10^{-13}$,calculate the concentration of $S^{2-}$ under both conditions.

For a weak acid $HCN$ at $25 \, ^\circ C$,which of the following statements is correct?

The $pH$ at which the maximum hydrate is present in a solution of oxaloacetic acid $(HOOC-CO-CH_2-COOH)$ with $pK_{a1} = 2.2$ and $pK_{a2} = 3.98$ is: