华东理工大学：《物理化学》课程教学课件（讲稿，英文版）06 Chapter 6 Physical transformation of pure substances.pdf_大学文库

版权所有：华东理工大学物理化学教研室 2 The simplest applications of thermodynamics to chemically significant systems are to the discussion of the phase transitions of pure substances. We shall see that a phase diagram is a map of the pressures and temperatures at which each phase of a substance is the most stable. 6. Physical transformation of pure substances

版权所有：华东理工大学物理化学教研室 3 In this chapter, we first describe the interpretation of empirically determined phase diagrams for a selection of materials; then we turn to a consideration of the factors that determine the positions and shapes of the boundaries between the regions on a phase diagram; and finally, we consider the thermodynamic discussion of liquid surfaces, such as surface tension and capillary action. 6. Physical transformation of pure substances

版权所有：华东理工大学物理化学教研室 4 Phase diagrams 6.1 The stabilities of phases 6.2 Phase boundaries 6.3 Three typical phase diagrams Phase stability and phase transitions 6.4 The thermodynamic criterion of equilibrium 6.5 The dependence of stability on the conditions 6.6 The location of phase boundaries 6.7 The Ehrenfest classification of phase transitions The physical liquid surface 6.8 Surface tension 6.9 Curved surfaces 6.10 Capillary action 6. Physical transformation of pure substances

版权所有：华东理工大学物理化学教研室 5 1). The phase α ( phasewater ) β phase oil )( h ρ 6.1 The stabilities of phases-Basic concepts A phase of a substance is a form of matter that is uniform throughout in chemical composition and physical state

版权所有：华东理工大学物理化学教研室 6 6.1 The stabilities of phases-Basic concepts 2). The phase transition A phase transition is the spontaneous conversion of one phase into another phase, occurs at the specific temperature for a given pressure. e.g. at 1 atm, ice is the stable phase below 0℃, but above 0 ℃ The schematic T dependence of the liquid water is the stable phase. chemical potential of the solid, liquid, and gas phases of a substance

版权所有：华东理工大学物理化学教研室 7 6.1 The stabilities of phases-Basic concepts 3). Ttrs A transition temperature, Ttrs, represents the temperature at which the two chemical potentials are equal and the two phases are in equilibrium at the specific pressure. Note that the normal transition The schematic T dependence of the temperature of p =1.0 atm chemical potential of the solid, liquid, and gas phases of a substance

版权所有：华东理工大学物理化学教研室 8 Phase diagrams 6.1 The stabilities of phases 6.2 Phase boundaries 6.3 Three typical phase diagrams Phase stability and phase transitions 6.4 The thermodynamic criterion of equilibrium 6.5 The dependence of stability on the conditions 6.6 The location of phase boundaries 6.7 The Ehrenfest classification of phase transitions The physical liquid surface 6.8 Surface tension 6.9 Curved surfaces 6.10 Capillary action 6. Physical transformation of pure substances

版权所有：华东理工大学物理化学教研室 9 6.2 Phase boundaries Phase equilibrium for one component system melting The solid phase freezing The liquid phase The solid The liquid The vapour vaporizing The liquid phase condensing The vapour phase The solid phase condensing The vapour phase sublimation The solid phase (α) transition The solid phase (β) phase(s)