Liquids and Solutions (8 lectures): 2nd Year Michaelmas Term
R.K.Thomas
Lecture Synopsis
This lecture course is the sequel to the introductory course "States of Matter", given in the Trinity term of the 1st Year. It examines the properties of liquids and solutions at both the thermodynamic and the molecular level. The topics break down as follows.
Description in terms of the radial distribution function (revision) and the way it is used in mixtures. The consequences of different levels of intermolecular forces on the radial distribution function and an overview of these consequences for ideal mixing, the regular solution model, electolyte solutions, and polymer solutions.
The thermodynamic properties of ideal solutions, Raoult's Law, Henry's Law, ideal solubility and osmotic pressure. Non-zero enthalpy of mixing and regular solutions. Activity and activity coefficient. Phase separation of two liquids. Real liquid mixtures and the hydrophobic effect.
Surface tension. The Gibbs equation relating surface excess and surface tension. Surface activity of amphiphilic molecules. The shape of the surface. Bubbles and the Laplace equation.
Polymer chain as a random walk. The relation between ideal and real chains. The dimensions of polymer chains in solution. The Flory-Huggins model of polymer solution thermodynamics.
The structure of hydrated ions. Outline of Debye-Huckel theory. Application of the Debye-Huckel limiting law to electrolyte effects on acid dissociation solubility of sparingly soluble salts, and in electrochemical cells.
8. Bibliography
Molecular Driving Forces by Dill & Bromberg, Garland Science, New York (2003)