Choose the correct option for the total pressure (in atm.) in a mixture of 4g O₂ and 2g H₂ confined in a total volume of one litre at 0$$^\circ$$C is :

[Given R = 0.082 L atm mol^$$-$$1K^$$-$$1, T = 273 K]

A mixture of N₂ and Ar gases in a cylinder contains 7g of N₂ and 8g of Ar. If the total pressure of the mixture of the gases in the cylinder is 27 bar, the partial pressure of N₂ is :
[Use atomic masses (in g mol^{$$ - $$1}) : N = 14, Ar = 40]

A gas at 350 K and 15 bar has molar volume 20 percent smaller than that for an ideal gas under the same conditions. The correct option about the gas and its compressibility factor (Z) is -

Given van der Waals’ constant for NH₃ , H₂, O₂ and CO₂ are respectively 4.17, 0.244, 1.36 and 3.59, which one of the following gases is most easily liquefied?