$P$ and $Q$ combines to form two compounds $\mathrm{PQ}_2$ and $\mathrm{PQ}_3$. If $1 \mathrm{~g} ~\mathrm{PQ}{ }_2$ is dissolved in 51 g benzene the depression of freezing point becomes $0 \cdot 8^{\circ} \mathrm{C}$. On the other hand if $1 \mathrm{~g} ~\mathrm{PQ}_3$ is dissolved in 51 g of benzene, the depression of freezing point becomes $0.625^{\circ} \mathrm{C}$. The atomic mass of P and Q are $\left(\mathrm{K}_{\mathrm{f}}\right.$ of benzene $=5 \cdot 1 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1})$

Identify the major product (G) in the following reaction

Increasing order of solubility of AgCl in (i) $\mathrm{H}_2 \mathrm{O}$, (ii) 1 M NaCl (aq.), (iii) 1 M CaCl 2 (aq.) and (iv) $1 \mathrm{M}~ \mathrm{NaNO}_3$ (aq.) solution

Arrange the following compounds in order of their increasing acid strength