Which of the following equations represents the ideal gas equation?

The density of a gas $A$ is three times that of a gas $B$. If the molecular mass of $A$ is $M$,the molecular mass of $B$ is:

$A$ glass vessel weighs $50.0 \, g$ when empty. When filled with a liquid of density $0.98 \, g \cdot mL^{-1}$,it weighs $148.0 \, g$. When filled with an ideal gas at $760 \, mm$ of $Hg$ pressure and $300 \, K$ temperature,it weighs $50.5 \, g$. Calculate the molar mass of the gas in $u$.

$34.05 \, mL$ of phosphorus vapour weighs $0.0625 \, g$ at $546^{\circ} C$ and $0.1 \, bar$ pressure. What is the molar mass of phosphorus?

Which of the following graphs represents Boyle's law?

In the equation $PV = nRT$,the number of moles per liter can be expressed as: