4.1 Introduction 4.2 Expressions of concentration 4.3 Partial molar properties 4.4 Two empirical laws in dilute liquid solutions 4.5 Chemical potential of each component in gaseous mixtures 4.6 Liquid mixtures 4.7 Chemical potential of each component in dilute liquid solutions . 4.8 Colligative properties in dilute liquid solutions 4.9 Gibbs-Duhem relations 4.10 Non-ideal liquid solutions 4.11 Distribution law