Physical Chemistry Chapter 7 One-component phase equilibrium For a one-component system(pure water) f=1→p+2=3p,(C=1) f20,p≥1,32p21 2 P=3,f=0
11 f＝1－p＋2＝3－p，(C＝1） f ≥0, p ≥1, 3≥p≥1 p＝1，f＝2 p＝2，f＝1 p＝3，f＝0 One-component phase equilibrium For a one-component system (pure water) Physical Chemistry Chapter 7
Physical Chemistry Chapter 7 The phase rule Phase diagram: shows the regions of pressure and temperature at which its various phases are thermodynamically stable Phase boundary: a boundary between regions, shows the values of p and t at which two phases coexist in equilibrium
12 The Phase Rule Phase diagram: shows the regions of pressure and temperature at which its various phases are thermodynamically stable. Phase boundary: a boundary between regions, shows the values of P and T at which two phases coexist in equilibrium. Physical Chemistry Chapter 7
Physical Chemistry Chapter 7 The phase rule SO iquid Critical riple i point point Solid Liquid Gas vapor I stable stable stable Solid-liquid phase boundary: a plot of the freezing point at various p Liquid-vapor phase boundary: a plot of the vapor P of li quid again nst T Solid-vapor phase boundary: a plot of the sublimation vapor P against T 13
13 The Phase Rule Solid-liquid phase boundary: a plot of the freezing point at various P. T3 Tc P T Gas stable Liquid stable Solid stable Tf Tb T Triple point Critical point vapor liquid solid Liquid-vapor phase boundary: a plot of the vapor P of liquid against T. Solid-vapor phase boundary: a plot of the sublimation vapor P against T. Physical Chemistry Chapter 7