In the Victor Meyer method,$0.2 \ g$ of a volatile substance displaces $56 \ mL$ of air at $STP$. The molar mass of the substance is:

Some $CO_2$ gas was kept in a sealed container at a pressure of $1 \ atm$ and at $273 \ K$. This entire amount of $CO_2$ gas was later passed through an aqueous solution of $Ca(OH)_2$. The excess unreacted $Ca(OH)_2$ was later neutralized with $0.1 \ M$ of $40 \ mL$ $HCl$. If the volume of the sealed container of $CO_2$ was $x$,then $x$ is $............. \ cm^3$ $(nearest \ integer)$.
$[$Given : The entire amount of $CO_{2(g)}$ reacted with exactly half the initial amount of $Ca(OH)_2$ present in the aqueous solution.$]$

If the concentration of $SO_4^{2-}$ in an aqueous solution of $Al_2(SO_4)_3$ is $0.27 \ M$,then the concentration of $Al^{3+}$ ions will be ....... $M$.

$417 \ g$ 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: .............. $\%$ $(P = 31, Cl = 35.5, O = 16, H = 1)$

What is the weight in $g$ of $90\%$ pure $H_2SO_4$ required to neutralize $5 \ g$ of caustic soda?

What is the volume of $4.4 \ g$ of $CO_2$ at $STP$ in $L$?