When $100 \, mL$ of $M/10 \, NaOH$ solution and $50 \, mL$ of $M/5 \, HCl$ solution are mixed,the $pH$ of the resulting solution would be:

When a standard solution of $NaOH$ is left in the air for a few hours,

$2.5 \ mL$ of $\frac{2}{5} \ M$ weak monoacidic base ($K_{b} = 1 \times 10^{-12}$ at $25^{\circ} C$) is titrated with $\frac{2}{15} \ M \ HCl$ in water at $25^{\circ} C$. The concentration of $H^{+}$ at equivalence point is ($K_W = 1 \times 10^{-14}$ at $25^{\circ} C$).

Statement $A$: Addition of $NH_4OH$ in the presence of excess $NH_4Cl$ to an aqueous solution of $BaCl_2$ results in the precipitation of $Ba(OH)_2$.
Reason $B$: $Ba(OH)_2$ is insoluble in water.

If $20 \, mL$ of $0.25 \, N$ strong acid and $30 \, mL$ of $0.2 \, N$ strong base are mixed,then the resulting solution is

Order of solubility of solid $AgCl_{(s)}$ in given cases.
$(i)$ In pure water
$(ii)$ In presence of $0.1 \ M$ $AgNO_3$
$(iii)$ In presence of $2 \ M$ $aq.$ solution of $KCN$
$(iv)$ In presence of $1 \ M$ $aq.$ solution of $Ca(CN)_2$
$(v)$ In presence of $2 \ M$ $aq.$ solution of $NH_3$
(Assuming $100 \%$ dissociation of $AgNO_3$,$KCN$ and $Ca(CN)_2$ and complex formation with $NH_3$ and $CN^{-}$ will take place.)