Solutions and Phase Rule

Paper Code: 
CHY- 313
Contact Hours: 
Max. Marks: 
Unit I: 
Ionic Equilibria

Strong, moderate and weak electrolytes, degree of ionization, factors affecting degree of ionization, ionization constant and ionic product of water. Ionization of weak acids and bases, pH scale, common ion effect; Dissociation constants of mono-, di- and tri- protic acids (exact treatment). Salt hydrolysis- Calculation of hydrolysis constant, degree of hydrolysis and pH for different salts. Buffer solutions:  Derivation of Henderson equation and its applications, Buffer capacity, buffer range, buffer action and applications of buffers in analytical chemistry and biochemical processes in the human body. Solubility and solubility product of sparingly soluble salts – Applications of solubility product principle. Qualitative treatment of acid – base titration curves (calculation of pH at various stages). Theory of acid – base indicators; Selection of indicators and their limitations. Multistage equilibria in polyelectrolyte systems; Hydrolysis and hydrolysis constants.



Unit II: 
Dilute Solutions– Colligative Properties

Introduction, colligative properties, Raoult’s law, relative lowering of vapour pressure; Osmosis, law of osmotic pressure and its measurement, Elevation of boiling point and its measurement,  Depression of freezing point and its measurement, Use of colligative properties in molecular weight determination; Non-ideal behaviour and Van’t Hoff’s factor ‘i’.



Unit III: 
Solutions and Non-ideal Solutions

Solutions: Ideal and non-ideal solutions, methods of expressing concentrations of solutions, Solution of gases in liquid: Henry’s law, deviation from Henry’s law. Non ideal system: Azeotropes –ethanol-water systems. Partially miscible liquids: phenol-water, trimethylamine-water, nicotine-water systems; Lower and upper consolute temperature, effect of impurity on consolute temperature; Immiscible liquids.



Unit IV: 
Heterogeneous Equilibria I

Introduction to phase, component and degree of freedom, derivation of Gibbs phase rule;

Phase equilibria of one component system-water, CO2 and sulphur system, liquid helium.

Phase equilibria of two component system-solid-liquid equilibria , simple eutectic – Bi-Cd, KI-H2O, Pb-Ag systems, desilverisation of lead.



Unit V: 
Heterogeneous Equilibria II

Solid solutions: compound formation with congruent melting point (Mg-Zn) and incongruent melting point (NaCl-H2O), (FeCl3 – H2O), (CuSO4 – H2O)and (Na2SO4–H2O) system; freezing mixtures (acetone – dry ice).

Phase diagrams for three component systems. Acetic acid –chloroform-water.



  1. A Text Book of Physical Chemistry; A.S. Negi, S.C. Anand; New Age International (P) Limited, New Delhi, 2002.
  2. The Elements of Physical Chemistry; P.W. Atkins; OxfordUniversity Press, 1996.
  3. Physical Chemistry; Seventh Edition; R.A. Alberty; Wiley Eastern Ltd., Singapore, 1987
  4. Physical Chemistry Through Problems; S.K. Dogra and S.Dogra; Wiley Eastern Ltd, New Delhi, 2001.



Academic Year: