The density of methane at $27\,^oC$ and $2.0\,atm$ pressure is ............ $g\,L^{-1}$.

An $LPG$ (Liquefied Petroleum Gas) cylinder weighs $15.0 \ kg$ when empty. When full, it weighs $30.0 \ kg$ and shows a pressure of $3.0 \ atm$. In the course of usage at $27^{\circ}C$, the mass of the full cylinder is reduced to $24.2 \ kg$. The volume of the used gas in cubic metre at the normal usage condition ($1 \ atm$ and $27^{\circ}C$) is (assume $LPG$ to be normal butane and it behaves ideally). (in $m^3$)

Which scientists formulated the gas laws based on the physical properties of gases? State their respective laws.

If $20 \ cm^3$ of gas at $1 \ atm$ is expanded to $50 \ cm^3$ at constant $T$,what is the final pressure?

$A$ vessel of $120 \, mL$ capacity contains a certain amount of gas at $35^{\circ} C$ and $1.2 \, bar$ pressure. The gas is transferred to another vessel of volume $180 \, mL$ at $35^{\circ} C$. What would be its pressure?

An air bag on adiabatic expansion undergoes $5 \%$ increase in its volume. The percentage change in pressure is $\left[\gamma_{air}=1.4\right]$ (in $\%$)