What are the limitations of Vander Waal's equation of state?

Write a short note on liquefaction of gases.

Explain what is meant by 'critical phenomenon'? What are 'critical constants' of a gas?

Describe briefly the Isotherm of Carbon dioxide.
Or
Briefly describe the Isotherm of Carbon dioxide as studied by Andrews.

What are the main postulates of Kinetic energy Molecular Theory of liquids?

On the basis of kinetic molecular theory of liquids, how can you explain the following properties of liquids:
(i) Volume                             (ii) Density
(iii) Compressibility                (iv) Diffusion?

What is evaporation? 

Explain briefly the factors on which evaporation depends.

What do you mean by heat of vaporisation? On what factors does it depend?

Explain briefly the term "vapour pressure" . What are the factors on which vapour pressure of a liquid depends?