$10 \ mL$ of an aqueous solution containing $222 \ mg$ of calcium chloride $(mol. wt. = 111)$ is diluted to $100 \ mL$. The concentration of chloride ion in the resulting solution is $..... \ mol/L$.

$10 \ mL$ of a gaseous hydrocarbon on combustion gives $40 \ mL$ of $CO_{2(g)}$ and $50 \ mL$ of $H_2O_{(g)}$. The hydrocarbon is $-$

The molarity of $2 \, N \, HCl$ is .......

The mass of $CO_2$ that will be obtained by heating $10 \ kg$ of $80 \%$ pure limestone $(CaCO_3)$ is ............... $kg$.

The volume of $0.1 \ M$ oxalic acid that can be completely oxidized by $20 \ mL$ of $0.025 \ M$ $KMnO_4$ solution is (in $mL$)

$417 \ g$ of $PCl_{5(s)}$ is kept in an open container where it reacts with moisture from air to form $POCl_{3(s)}$ and $HCl_{(g)}$. $A$ few hours later,the solid left in the container weighed only $395 \ g$. The percentage of $PCl_5$ converted to $POCl_3$ is: .............. $\%$ $(P = 31, Cl = 35.5, O = 16, H = 1)$