Different States of Matter

Concept of pressure and temperature. Nature of distribution of velocities in one, two and three dimensions. Maxwell's distribution of speeds. Kinetic energy distribution in one, two and three dimensions, calculations of average, root mean square and most probable values in each case; Calculation of number of molecules having energy ≥ ε, Principle of equipartition of energy and its application to calculate the classical limit of molar heat capacity of gases. 

Collision of gas molecules, collision diameter; collision number and mean free path, frequency of binary collisions (similar and different molecules); wall collision and rate of effusion. Deviation of gases from ideal behaviour; compressibility factor; Andrew's and Amagot's plots; van der Waals equation and its characteristic features. Existence of critical state. Critical constants in terms of van der Waals constants. Law of corresponding states and significance of second virial coefficient. Boyle temperature. Intermolecular forces (Debye, Keesom and London interactions; Lennard-Jones potential, elementary idea).

Nature of the liquid state, (short range order and long range disorder). Vapour pressure, surface tension, surface energy, excess pressure, capillary rise and measurement of surface tension. Work of cohesion and adhesion, spreading of liquid over other surface. Vapour pressure over curved surface. Temperature dependence of surface tension. General features of fluid flow (streamline flow and turbulent flow). Reynold number, nature of viscous drag for streamline motion. Newton's equation, viscosity coefficient. Poiseuille's equation (with derivation), temperature dependence of viscosity, principle of determination of viscosity coefficient of liquids by falling sphere method. Viscosity of gases vs. liquids and kinetic theory of gas viscosity.

Nature of the solid state, law of constancy of interfacial angles, law of rational indices, Miller indices, seven crystal systems and fourteen Bravias lattices; X-ray diffraction, Bragg’s law, a simple account of rotating crystal method and powder pattern method. Analysis of powder diffraction patterns of NaCl, CsCl and KCl. Defects in crystals. Glasses and liquid crystals.