The gas equation $PV = nRT$ is applicable for which of the following conditions?

$1 \ L$ closed flask contains a mixture of $4 \ g$ of methane and $4.4 \ g$ of carbon dioxide. The pressure inside the flask at $27^{\circ} C$ is [Assume ideal behaviour of gases] (in $atm$)

If $2.5$ moles of an ideal gas at a certain temperature are allowed to expand isothermally and reversibly from an initial volume of $2$ $dm^3$ to $20$ $dm^3$, the work done by the gas is $-16.5$ $kJ$. The temperature (in $K$) of the gas is (Round off to the nearest value). $(R = 8.314 \ J \ K^{-1} \ mol^{-1})$

Which of the following expressions at constant pressure represents Charles's law?

Explain the relationship between the moles of a gas,its volume,and its density.

Which one of the following is the correct $PV$ vs $P$ plot at constant temperature for an ideal gas? ($P$ and $V$ stand for pressure and volume of the gas respectively)