'a’ and `b’ are van der Waals’ constants for gases. Chlorine is more easily liquefied than ethane because

If 10^–4 dm³ of water is introduced into a 1.0 dm³ flask to 300 K, how many moles of water are in the vapour phase when equilibrium is established ?
(Given : Vapour pressure of H₂O at 300 K is 3170 Pa ; R = 8.314 J K^–1 mol^–1)

Equal masses of methane and oxygen are mixed in an empty container at 25^oC. The fraction of the total pressure exerted by oxygen is

Which one of the following statements is NOT true about the effect of an increase in temperature on the distribution of molecular speeds in a gas?