An ideal gas will have maximum density when

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 $m^3$)

If two moles of an ideal gas at $546 \ K$ occupy a volume of $44.8 \ L$,the pressure must be ............. $atm$.

At $0\, ^\circ C$,$4\, g$ of $O_2$ and $2\, g$ of $H_2$ are filled in a $1\, L$ bulb. What will be the total pressure of the mixture (in $, atm$)?

The density of oxygen gas at $1.0 \, atm$ pressure and $27 \, ^oC$ temperature is ............. $g/L$.

Pay load is defined as the difference between the mass of displaced air and the mass of the balloon. Calculate the pay load when a balloon of radius $10 \, m$,mass $100 \, kg$ is filled with helium at $1.66 \, bar$ at $27^{\circ} C$. (Density of air $= 1.2 \, kg \, m^{-3}$ and $R = 0.083 \, bar \, dm^{3} \, K^{-1} \, mol^{-1}$).