The deviation of a gas from ideal behavior can be expressed by which of the following?

The ratio of densities of two gases is $1 : 2$. If the ratio of their temperatures is $2 : 1$,find the ratio of their corresponding pressures. (Assume the molar masses of the gases are equal.)

$n$ moles of an ideal gas at temperature $T$ (in kelvin) occupy $V \ L$ of volume, exerting a pressure of $P$ atmospheres. What is the concentration (in $mol / L$)?

$0.5 \, mol$ of gas $A$ and $x \, mol$ of gas $B$ exert a pressure of $200 \, Pa$ in a container of volume $10 \, m^3$ at $1000 \, K$. Given $R$ is the gas constant in $J \, K^{-1} \, mol^{-1}$,$x$ is

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

Which effect is observed when the pressure of a gas increases?