Critical point Critical point (374c,218atm) (31c,73atm) SOLID LIQUID SOLID LIQUID Melting/ Freezing 1.0 Sublimation/ Vaporization/ Triple point Deposition Condensation (0.01c,0.006atm) GAS 1.0 Triple point (-57C,5.1atm) GAS -78 31 -1 100 Temperature (C)- Temperature(C). A CO2 B H2O Phase diagrams for carbon dioxide and water 16 PDF文件使用"pdfFactory Pro”试用版本创建m,fineprint.com,c四
16 Phase diagrams for carbon dioxide and water PDF 文件使用 "pdfFactory Pro" 试用版本创建 Ìwww.fineprint.com.cn
There is just one point,called the triple point where all three phases co-exist. There are curves on a phase diagram along which the two phases on either side of the curve may co-exist at equilibrium. There is a point called the critical point above which liquid cannot co-exist with vapour. 17 PDF文件使用"pdfFactory Pro”试用版本创建mm,fineprint.com,cn
17 There is just one point, called the triple point where all three phases co-exist. There are curves on a phase diagram along which the two phases on either side of the curve may co-exist at equilibrium. There is a point called the critical point above which liquid cannot co-exist with vapour. PDF 文件使用 "pdfFactory Pro" 试用版本创建 ÿwww.fineprint.com.cn
Two-component systems When two components are present in a system, C=2F=C-P+2=2-P+2=4-P Fmin=0 Pmax=4---the maximum value of P for two- component systems. Pmin=1 Fmax=3---temperature,pressure and the composition If we keep a variable constant,one of the degrees of freedom has been discarded. Now Pmin=1 Fmas=2 ,Hence, (a)one form of the phase diagram is a map of pressure and composition(in this case,T could be held constant) (b)The other phase diagram depicted in terms of temperature and composition.(P could be held constant) 18 PDF文件使用"pdfFactory Pro”试用版本创建m,fineprint.com,c四
18 Two-component systems When two components are present in a system, C=2 F=C-P+2=2-P+2=4-P Fmin=0 Pmax=4---the maximum value of P for twocomponent systems. Pmin=1 Fmax=3---temperature,pressure and the composition If we keep a variable constant, one of the degrees of freedom has been discarded. Now Pmin=1 Fmax=2 ,Hence, (a) one form of the phase diagram is a map of pressure and composition(in this case, T could be held constant) (b)The other phase diagram depicted in terms of temperature and composition.(P could be held constant) PDF 文件使用 "pdfFactory Pro" 试用版本创建 Ìwww.fineprint.com.cn
Vapour pressure diagrams-- ideal solution How to construct liquid-vapour composition diagrams P↑ T=Const At constant T: (P] PA=PAXA=PA(1-XB),PB=PE"XB P=PA+PB=PA+(PB-PA)XB P~Xg as the right Fig.(blue line) YB-PE/P P~Yg as the right Fig.(red line) B 19 PDF文件使用"pdfFactory Pro”试用版本创建w.fineprint.com.cn
19 Vapour pressure diagrams--- ideal solution How to construct liquid-vapour composition diagrams At constant T: PA=PA *ΧA=PA * (1-ΧB ),PB=PB *ΧB P=PA+PB=PA *+(PB * -PA * )ΧB P~ΧB as the right Fig.(blue line) YB=PB/P P~YB as the right Fig.(red line) PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.com.cn