简单混合物 Simple mixtures 偏摩尔体积 Partial molar Volume V≠V1+V 1+1≠2 Add 1.0 mol ho Add 1.0 mol Ho Volume increases Volume increases by 18 cm'mol Large H○ EtoH by 14 cm'mol volumes Molar volume of ho: Partial molar volume of 18 cm mol 1 HO in EtoH: 14 cm mol 1 Partial molar volume of substance a in a mixture is the change in volume per mole of a added to the large volume of the mixture
简单混合物 Simple Mixtures 偏摩尔体积 Partial Molar Volume Partial molar volume of substance A in a mixture is the change in volume per mole of A added to the large volume of the mixture. V V1 + V2 1 + 1 2
偏摩尔体积 Partial molar Volume The partial molar volume of components of a mixture vary as the mixture goes from pure a to pure B- that is because the molecular environments of each molecule change (i.e, packing, solvation, etc. 58 56 18 54 85019>56556E页 物质J的偏摩尔体积V PT.n' a14 2 04 06 Mole fraction of ethand, X(C HS OH
偏摩尔体积 Partial Molar Volume 物质 J 的偏摩尔体积 VJ P,T ,n' J J n V V =
偏摩尔体积 Partial molar volume va ∨(b) J/pTn )偏摩尔体积与组成有关. (2)b点处的偏摩尔体积为负(此时, 日 b 加物质A会使总体积变小) Composition, n For a binary mixture, the composition can be changed by addition of dna of a and dng of B with the total volume changing by on P.7,B A′A BB
偏摩尔体积 Partial Molar Volume (1) 偏摩尔体积与组成有关. (2) b点处的偏摩尔体积为负 (此时, 加物质A会使总体积变小). P,T ,n' J J n V V =
化学势 Chemical potential G 化学势μ p, I,n 偏摩尔 Gibbs能 (a) u(b) Total Gibbs energy Is G nR u B B Composition n
化学势 Chemical Potential 化学势 偏摩尔Gibbs能
化学势 Chemical potential Gibbs energy depends on composition, pressure and temperature(so, G may change if any of these variables change - which they may )For a system with components A, B dG= vdp ST+A如A+HB2mB+… which is the fundamental equation of classical thermodynamics At constant temperature and pressure, BB Recall e max dG △G e. max in+ e. max NA B What does this mean? Non-expansion work can happen just from changing system composition at constant pressure and temperature (e.g., battery, chemical rxn in two sites called electrodes, and the work the battery produces comes from reactants going to products
化学势 Chemical Potential Recall: