Which of the following undergoes hydrolysis when dissolved in water?

Identify the correct statements from the following.
$(A)$ The ionic product of water at $100^{\circ} C$ is $< 10^{-14}$.
$(B)$ $pH$ of a solution decreases with increasing temperature.
$(C)$ $NaH_2PO_4$ on hydrolysis gives a basic solution.
$(D)$ $NH_3$ can act both as Bronsted acid and base.

Assign $A, B, C, D$ from the given type of reaction.
$Cu(OH)_2 \downarrow + 4NH_3(soln.) \longrightarrow [Cu(NH_3)_4]^{2+} + 2OH^{-}$

When dilute $H_2SO_4$ is added to an aqueous solution of potassium chromate,the yellow color of the solution changes to orange. This indicates that .....

$A$ certain amount of $H_2CO_3$ and $HCl$ are dissolved to form $1 \ L$ solution. At equilibrium,it is found that the concentrations of $H_2CO_3$ and $CO_3^{2-}$ are $0.1 \ M$ and $0.01 \ M$ respectively. Calculate the $pH$ of the solution. Given that for $H_2CO_3$,$K_{a_1} = 10^{-5}$ and $K_{a_2} = 10^{-8}$.

$20 \ mL$ of $0.5 \ N \ HCl$ and $35 \ mL$ of $0.1 \ N \ NaOH$ are mixed. The resulting solution will