Which among the following gases can be liquified easily?

• Chlorine

• Nitrogen

• Oxygen

• Hydrogen

If average velocity of a sample of gas molecules at 300 K is 5 cm s^-1, what is RMS velocity of same sample of gas molecules at the same temperature? (Given, α: u: v = 1:1.224: 1.127)

• 6.112 cm/s

• 4.605 cm/s

• 4.085 cm/s

• 5.430 cm/s

3.

Two closed bulbs of equal volume (V) containing an ideal gas initially at pressure p_i and temperature T₁ are connected through a narrow tube of negligible volume as shown in the figure below. The temperature of one of the bulbs is then raised to T₂. The final pressure p_f is:

• 
• 
• 
• 

The intermolecular interaction that is dependent on the inverse cube of the distance between the molecule is:

• ion-ion interaction

• ion-dipole interaction

• London force

• London force

If Z is a compressibility factor, Vander Waal's equation at low pressure can be written as 

For the gaseous state, if most probable speed is denoted by C*, average speed by C and mean square speed by C, then for a large number of molecules the ratios of these speeds are:

The compressibility factor for a real gas at high pressure is

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

• a and b for Cl₂ > a and b for C₂H₆

• a and b for Cl₂ < a and b for C₂H₆

• a and Cl₂ < a for C₂H₆ but b for Cl₂ > b for C₂H₆

• a and Cl₂ < a for C₂H₆ but b for Cl₂ > b for C₂H₆

If 10^–4 dm³ of water is introduced into a 1.0 dm³ flask at 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 P_a; R = 8.314 J K^–1 mol^–1)

• 5.56 x 10^-3 mol

• 1.53 x 10^-2 mol

• 4.46 x 10^-2 mol

• 4.46 x 10^-2 mol

Assuming that water vapour is an ideal gas, the internal energy change(∆U) when 1 mol of water is vapourised at 1 bar pressure and 100°C, (Given: Molar enthalpy of vapourisation of water at 1 bar and 373 K = 41 kJ mol^-1 and R = 8.3 J mol^–1K^–1 will be) –

• 4.100 kJ mol^–1

• 3.7904 kJ mol^–1

• 37.904 kJ mol^–1

• 37.904 kJ mol^–1