厦门大学：《物理化学 Physical Chemistry》课程电子教案（PPT教学课件，英文版）chapter12-2 Multicomponent Phase Equilibrium

physical Chemistry Multicomponent Phase Chapter 12 Multicomponent phase Equilibrium

1 Chapter 12 Multicomponent Phase Equilibrium Physical Chemistry Multicomponent Phase

Physical Chemistr Multicomponent Phase Two-component solid-liquid equilibrium liquid-phase miscibility and solid-phase immiscibility Bc Freezing points of b&C T R Fig 12.19 Curve AFGE liquid solution e Freezing-point-depression S )of B+C curve of c due to solute B H G D Crve①E 2 1.s.+C(s)I S e Freezing-point-depression K E/ B(S curve of b due to solute c Pointe The eutectic point s solid b+solid C ta The eutectic temperature 0 XB BB imple eutectic system B

2 Two-component solid-liquid equilibrium * TB * TC Freezing points of B & C Curve AFGE S solid B+solid C K H F R liquid solution (l.s.) of B+C G E D * TB * TC T1 T2 T3 T xB ' B x '' B x l.s.+ B(s) l.s.+C(s) ''' B 0 x 1 I Fig. 12.19 A Freezing-point-depression curve of C due to solute B Curve DE Freezing-point-depression curve of B due to solute C Point E The eutectic point T3 The eutectic temperature Liquid-phase miscibility and solid-phase immiscibility Simple eutectic system Physical Chemistry Multicomponent Phase

Physical Chemistry Multicomponent Phase Example Cd-Bi二元相图 96 A546 熔化物(单相) C eutectic 下|B+熔化粉、 point 熔化物+Cd 413 B E D G K 020.40.60.8 B Cd的质量分数 100%1 100% Pure Bi eutectic mixture Pure Cd

3 Cd-Bi二元相图 Physical Chemistry Multicomponent Phase Pure Bi eutectic mixture Pure Cd Example eutectic point

二组分固态部分互熔,液态完全互溶系统的液固平衡相图 具有低共熔点的熔点-组成图 350 CED--Sa(A+B)+Sp(A+B)+IE(A+B C 327读图要点: 300 I(A+B) ①点、线、区的含义 250 AtB) 2w/A+B)n/(A+B②对比二组分液态部分 0.71 互溶系统的沸点-组成图 (A+B) 00110.26 150 ③理解三相平衡线的含义 sa(a+B)+sB(a+B) 096 G 0.00.2040.60.810 Sn(a) Pb(B) Sn(A)-Pb(B)系统的熔点组成图

4 二组分固态部分互熔，液态完全互溶系统的液固平衡相图 读图要点： ① 点、线、区的含义 ②对比二组分液态部分 互溶系统的沸点-组成图 ③理解三相平衡线的含义 CED — s(A+B)+ s (A+B)+lE (A+B) 具有低共熔点的熔点-组成图 0.0 0.2 0.4 0.6 0.8 1.0 300 250 150 200 Sn(A) Pb(B) xB l(A+B) t/℃ l(A+B) C D E 350 s (A+B) + s (A+B) s(A+B)+ s (A+B) s(A+B) * A t * B t 327 232 0.011 0.26 0.71 F 0.96 G Sn(A) - Pb(B)系统的熔点-组成图 • • • • • • •

0.00.2040.60.81.0 ℃[P=常数 120 B20.58 g(A+B tre 100 (A+B)=l(A+B) B 327 E D 00 I(A+B) 80L/A la(A+B)→b(A+B) I(A+B) A 60 200Lc E/ SB(A+B)n/sB(A+B F G 0.71 00110.26 0.00.20.40.60.8 0 150s(A+B) H,O(A n-CAHOOH(B sa(a+B)+ SB(A+B) 0.96 000.2040.60.81.0 Pb(b)

5 0.0 0.2 0.4 0.6 0.8 1.0 * B t * A t g(A+B) H2O(A) wB n-C4H9OH(B) wB t/℃ 120 100 60 80 0.0 0.2 0.4 0.6 0.8 1.0 l (A+B) l (A+B) P1=常数 wB=0.58 l (A+B) l (A+B) F G C E D g(A+B) l  (A+B) • • • • • • 0.0 0.2 0.4 0.6 0.8 1.0 300 250 150 200 Sn(A) Pb(B) xB l(A+B) t/℃ l(A+B) C D E 350 s (A+B) + s (A+B) s(A+B)+ s (A+B) s(A+B) * A t * B t 327 232 0.011 0.26 0.71 F 0.96 G • • • • • • •

Physical Chemistry Multicomponent Phase Two-component solid-liquid equilibrium Liquid-phase miscibility and solid-phase miscibility Solid solutions Interstitial solid solution Formed by substances with small atoms or molecules occupying interstices(holes)in the crystal structure of another substance Substitutional solid solution Formed by substances with atoms. molecules. or ions of similar size and structure

6 Two-component solid-liquid equilibrium Solid solutions Liquid-phase miscibility and solid-phase miscibility Interstitial solid solution Substitutional solid solution Formed by substances with atoms, molecules, or ions of similar size and structure. Formed by substances with small atoms or molecules occupying interstices (holes) in the crystal structure of another substance. Physical Chemistry Multicomponent Phase

Physical Chemistry Multicomponent Phase e Two-component solid-liquid equilibrium Liquid-phase miscibility and solid-phase miscibility T Fig.1220 Same pairs of substances are com npletely miscible in the solid state liquid solution(ls) e When the two miscible solids form an approximately ideal ● solid solution Compared to Fig. 12.12 solid solution

7 Two-component solid-liquid equilibrium Liquid-phase miscibility and solid-phase miscibility solid solution liquid solution (l.s.) T xNi 0 1 Fig. 12.20 Cu Ni Same pairs of substances are completely miscible in the solid state. When the two miscible solids form an approximately ideal solid solution Compared to Fig. 12.12 Physical Chemistry Multicomponent Phase

Physical Chemistry Multicomponent Phase Two-component solid-liquid equilibrium Liquid-phase miscibility and solid-phase partialmiscibility When the two miscible solids form a solid solution, but there are large deviations from ideality Melt Liquid solution (melt) Solid solution 313 Solid solution 43 p-CBHalCl B d-C1oH14=NOH A-C1oH:4=NOH Showing a minimum Showing a maximum

8 Two-component solid-liquid equilibrium Liquid-phase miscibility and solid-phase partial miscibility When the two miscible solids form a solid solution, but there are large deviations from ideality. Solid solution Liquid solution (melt) Solid solution Melt Showing a minimum Showing a maximum Physical Chemistry Multicomponent Phase

Physical Chemistry Multicomponent Phase a Two-component solid-liquid equilibrium t Liquid-phase miscibility and solid-phase partial miscibility Liquid solution (Is) a phase Phase- Solid ag saturated with cu transition loop β phase 1.s.+B Solid cu saturated with ag + Miscibility gap 1 Fig 12.22 g

9 Ag Cu 0 1 Two-component solid-liquid equilibrium Liquid-phase miscibility and solid-phase partial miscibility Liquid solution (l.s.)  +    l.s. +  l.s.+ Miscibility gap Phase￾transition loop  phase Solid Ag saturated with Cu  phase Solid Cu saturated with Ag Physical Chemistry Multicomponent Phase Fig. 12.22

physical Chemistry Multicomponent Phase S a peritectic phase transition is one where heating transforms a e solid phase to a liquid phase plus a second solid phase S(A+B)1200℃ Sp(A+B)+lE t/℃C The peritectic temperature I(A+B) B 1200C 1772 1600 I(A+B) f=3-0+2=1 1200 E/HC SB(A+B) D .P is fixed, /=0 961 800}A Sa(AtB)\+ Sa(atB) F ECD-IE(A+B) 9(A+B)2 +sa(atB 0.00.20.40.60.81.0 SB(A+B) Ag(A) P(B)10

10 s (A+B) 1200 ℃ s (A+B) + lE ECD — lE (A+B) +s (A+B) + s (A+B) The peritectic temperature: 1200 oC A peritectic phase transition is one where heating transforms a solid phase to a liquid phase plus a second solid phase: 0.0 0.2 0.4 0.6 0.8 1.0 2000 1600 800 1200 Ag(A) Pt(B) xB l(A+B) t/℃ l(A+B) C D E s (A+B) + s(A+B) s(A+B) * A t * B t 1772 961 G F + s (A+B) s (A+B) f = 3－φ＋2 = 1 H P is fixed, f = 0 Physical Chemistry Multicomponent Phase