Among the gases a, b, c , d, e and f, the gases that show only positive deviation from ideal behaviour at all pressures in the graph are

When the temperature of a gas is increased from $$30^{\circ} \mathrm{C}$$ to $$930^{\circ} \mathrm{C}$$, the root mean square speed of the gas would

Three flasks of equal volume contain $$\mathrm{CH}_4, \mathrm{CO}_2$$ and $$\mathrm{Cl}_2$$ gases respectively. They will contain equal number of molecules, if

Which among the following statements is/are incorrect regarding real gases?

(i) Their compressibility factor is never equal to unity (Z $$\ne$$ 1).

(ii) The deviations from ideal behaviour are less at low pressures and high temperatures.

(iii) Intermolecular forces among gas molecules are equal to zero.

(iv) They obey van der Waals’ equation, $$pV = nRT$$