Ideal solution model uA(=uA 8), at equilibrium uA(D=uA+Rtin(palp) uA(=uA+RTIn(palp)+rTinx HA(D=UA+RTInxa where ua is the chemical potential of the pure liquid Chemistry 331
Chemistry 331 Ideal Solution Model A A A A A A A A A A A A l g l RT p p l RT p p RT x l RT x ( ) ( ) ( ) ln( / ) ( ) ln( / ) ln ( ) ln * * = = + = + + = + , at equilibrium 0 0 0 0 where A * is the chemical potential of the pure liquid
Ideal heat of mixing △G mixing nAua+nBuB-naua+bUb) nRTInxtnBrtinxB a △S uXIn 1g=nGInx+nprInx 18 ˇB △H=△G…+TS=0 muxing muxing muxing Chemistry 331
Chemistry 331 Ideal Heat of Mixing G n n n n n RT x n RT x S G T n R x n R x H G T S mixing A A B B A A B B A A B B mixing mixing p A A B B mixing mixing mixing = + − + = + = = + = + = ( ) ln ln ln ln * * 0
Molecular basis for ideal sol'ns In pure liquid a, there are only A-A interactions In pure liquid b, there are only B-b interactions D In solutions of a and b there are A b interactions as well 0 says that all 78 three interactions are of equal strength Chemistry 331
Chemistry 331 Molecular Basis for Ideal Sol’ns. • In pure liquid A, there are only A-A interactions. • In pure liquid B, there are only B-B interactions. • In solutions of A and B, there are A-B interactions as well. ▪ Hmixing= 0 says that all three interactions are of equal strength
Ethyl acetate- Acetic Anhydride 800 700 600 500 Ptotal 400 Ethyl acetate 300 200 Pa drid 0.0010.20.3040.506070809 1.0 Chemistry 331
Chemistry 331 Ethyl Acetate - Acetic Anhydride 0 100 200 300 400 500 600 700 800 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 p /torr xethyl acetate pacetic andydride pethyl acetate ptotal
n-Pentane and methyl Acetate 600 total 400 Pp pentane 300 200联 FE-I methyl acetate 100 0.0 0.2 0.4 0.6 0.8 0 Chemistry 331 pentane
Chemistry 331 n-Pentane and Methyl Acetate 0 100 200 300 400 500 600 0.0 0.2 0.4 0.6 0.8 1.0 xpentane p /torr pmethyl acetate ppentane ptotal