5.1 The conditions of chemical equilibrium and affinity of chemical reaction 5.2 The equilibrium constant of a reaction and isothermal equation 5.3 Heterogeneous chemical equilibrium 5.4 Determination of equilibrium constants 5.5 The standard Gibbs function of formation 5.8 Coupling reaction 5.7 Chemical equilibrium of simultaneous reaction 5.6 The response of reactions to the conditions