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

What is the $pH$ of a solution containing $10 \, mL$ of $0.1 \, M \, NaOH$ and $10 \, mL$ of $0.05 \, M \, H_2SO_4$?

Calculate the molar solubility of $AgCl$ at $25\,^oC$ in $3.0\ M\ NH_3$ ($K_{sp}$ of $AgCl = 2.0 \times 10^{-10}$,$K_f$ of $[Ag(NH_3)_2]^+ = 1.25 \times 10^7$) (in $M$)

Estimate the approximate $pK_a$ of $0.5 \ M$ $CH_3COOH$. Degree of dissociation (ionisation) is $0.15$ $(\log 1.32 = 0.12)$.

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.

When $100 \ mL$ of $1 \ M$ $NaOH$ solution is mixed with $10 \ mL$ of $10 \ M$ $H_2SO_4$,the resulting mixture will be