New Chemistry 163B Multicomponent Phase Rule, Phase Diagram,...

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Chemistry 163B Multicomponent Phase Rule, Phase Diagram, Ideal Solutions, Osmosis 1 1 Chemistry 163B Multicomponent Phase Rule Solution Behavior and Misc Handout 2 phase rule and Cd-Bi phase diagram Cd (s) +Bi (s) liquid + Cd(s) liq+ Bi(s) liquid f=2+c-p c=2 (Ni, Cd) f=4-p set P=1atm f reaining =3-p variables: T, χ Cd in liquid Cd (s) +Bi (s) P= 1 atm "χ Cd "3 Listen up!!! UNDERSTAND THE FOLLOWING DISCUSSION OF THE PHASE RULE AND THIS BINARY COMPONENT PHASE DIAGRAM it may be very good for your future happiness 4 phase rule and Cd-Bi phase diagram Cd (s) +Bi (s) liquid f=2+c-p c=2 f=4-p set P=1atm f reaining =3-p variables: T, χ Cd liquid, p=1, f=2 T, χ cd , vary solid < 146° C, p=2, f=1 T, vary note: Cd(s) and Bi(s) are pure solids 5 phase rule and Cd-Bi phase diagram liquid + Cd(s) liq+ Bi(s) f=2+c-p c=2 f=4-p set P=1atm f reaining =3-p variables: T, χ Cd liquid + Cd(s), p=2, f=1 T or χ cd can vary Cd(s) just appears lower T χ Cd fixed χ Cd 6 phase rule and Cd-Bi phase diagram (eutectic) liquid + Cd(s) liq+ Bi(s) liquid +Cd(s) + Bi(s) p=3, f=0 T and χ cd fixed Cd(s) just appears Bi(s) just appears eutectic=constant freezing composition (mixture) T=146° C, χ Cd =0.55 =0.39 wt% Cd (s) +Bi (s)

Transcript of New Chemistry 163B Multicomponent Phase Rule, Phase Diagram,...

Page 1: New Chemistry 163B Multicomponent Phase Rule, Phase Diagram, …switkes.chemistry.ucsc.edu/teaching/CHEM163B/HANDOUTS/... · 2009. 3. 3. · Chemistry 163B Multicomponent Phase Rule,

Chemistry 163BMulticomponent Phase Rule, Phase Diagram, Ideal Solutions, Osmosis

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Chemistry 163B Multicomponent Phase Rule

Solution BehaviorandMisc

Handout

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phase rule and Cd-Bi phase diagram

Cd (s) +Bi (s)

liquid + Cd(s)liq+ Bi(s)

liquid

• f=2+c-p• c=2 (Ni, Cd)• f=4-p• set P=1atm• freaining=3-p• variables:

T, χ Cd in liquid Cd (s) +Bi (s)

P= 1 atm

"χ Cd "→

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Listen up!!!

UNDERSTAND THE FOLLOWING DISCUSSIONOF THE PHASE RULE AND THIS

BINARY COMPONENT PHASE DIAGRAM

it may be very good for your future happiness

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phase rule and Cd-Bi phase diagram

Cd (s) +Bi (s)

liquid

• f=2+c-p• c=2• f=4-p• set P=1atm• freaining=3-p• variables:

T, χ Cd

liquid,p=1, f=2T, χ cd, vary

solid < 146° C,p=2, f=1T, varynote: Cd(s)

and Bi(s) arepure solids

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phase rule and Cd-Bi phase diagram

liquid + Cd(s)liq+ Bi(s)

• f=2+c-p• c=2• f=4-p• set P=1atm• freaining=3-p• variables:

T, χ Cd

liquid + Cd(s),p=2, f=1T or χ cd

can varyCd(s)just appears

lower Tχ Cd fixed

χ Cd

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phase rule and Cd-Bi phase diagram (eutectic)

liquid + Cd(s)liq+ Bi(s)

liquid +Cd(s) + Bi(s)p=3, f=0

T and χ cd

fixed

Cd(s)just appears

Bi(s)just appears

eutectic=constant freezing composition (mixture)

T=146° C,χ Cd=0.55

=0.39 wt%Cd (s) +Bi (s)

Page 2: New Chemistry 163B Multicomponent Phase Rule, Phase Diagram, …switkes.chemistry.ucsc.edu/teaching/CHEM163B/HANDOUTS/... · 2009. 3. 3. · Chemistry 163B Multicomponent Phase Rule,

Chemistry 163BMulticomponent Phase Rule, Phase Diagram, Ideal Solutions, Osmosis

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not all solid-solid mixtures form eutectics

NaAlSi3O8 + CaAl2Si2O8 Cu + Ni

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Ideal Solutions

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Molecular Basis for Ideal Molecular Basis for Ideal Sol’nsSol’ns..

In pure liquid A, there are In pure liquid A, there are only only AA--AA interactions.interactions.In pure liquid B, there are In pure liquid B, there are only only BB--BB interactions.interactions.In solutions of A and B, In solutions of A and B, there are there are AA--BB interactions as interactions as well.well.∆∆HHmixingmixing= 0= 0means that all three means that all three interactions are of equal interactions are of equal strengthstrength..

http://classweb.gmu.edu/sdavis/chem331/engel9x.ppt10

Ideal Solutions

I. The partial molar volume of each component in solution is the same as its molar volume in pure liquid and thus the volume of the solution is the additive volume of the pure components

II. The enthalpy of mixing is zero:

III. The free energy of mixing is:

IV. The entropy of mixing is:

lnmix k kk

G n RT X∆ = ∑

lnmix mixmix k k

k

H GS n R XT

∆ − ∆∆ = = −∑

0mixH∆ =

i iV V •= i ii

V nV= ∑

from: http://www.chemistry.ucsc.edu/teaching/switkes/CHEM163B/HANDOUTS/ideal_soln_thermo.pdf

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liqliq ↔ ↔ vapvap EqEq. in Binary Mixtures. in Binary MixturesBoth the liquid and the Both the liquid and the vapor phase are binary vapor phase are binary mixtures of A and B.mixtures of A and B.xx AA, x, x BB are the mole are the mole fractions in the liquid.fractions in the liquid.yy AA, y, y BB are the mole are the mole fractions in the vapor.fractions in the vapor.pp AA, p, p BB are the partial are the partial pressures in the vapor.pressures in the vapor.

http://classweb.gmu.edu/sdavis/chem331/engel9x.ppt 12

benzene-toluene, quite ideal !!

http://www.chem.ucsb.edu/coursepages/06fall/1C-Watts/dl/Lecture_Notes/Lecture16.%2011-8-06Colligative%20Properties%20Solutions.pdf

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Chemistry 163BMulticomponent Phase Rule, Phase Diagram, Ideal Solutions, Osmosis

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Ethyl Acetate/Acetic AnhydrideEthyl Acetate/Acetic Anhydride

0

100

200

300

400

500

600

700

800

0.0 0.2 0.4 0.6 0.8 1.0

xethyl acetate

p /to

rr

http://classweb.gmu.edu/sdavis/chem331/engel9x.ppt14

Listen up!!!

UNDERSTAND THE FOLLOWING DISCUSSIONOF THE PHASE RULE AND THIS

BINARY COMPONENT PHASE DIAGRAM

it may be very good for your future happiness

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T vs X (P=1 atm) for solution-vapor equilibrium TOLUENE + BENZENE

toluene (b.p.=383.78) + benzene (b.p.=353.25)

tol+ben (solution)[fremaining=2]

tol+ben (vapor)[fremaining=2]

solution + vapor

[fremaining =1]

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fractional distillation

http://www.wpbschoolhouse.btinternet.co.uk/page12/gifs/FracDistRed.gif

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fractional distillation [Tbp vs (Xbenzene)solution]

bp

•vap benbenzene

•ben

(∆H )P (T) 1 1• ln =- -1 atm R T (T )

vap ben•

benbp

vap tol•

tolbp

(∆H ) 1 1- -• R T (T )benzene

(∆H ) 1 1- -• R T (T )toluene

P (T)• =e

1 atm

P

vapor pressure of benzene at T

vapor pressure of toluene at(

TT)

• =e 1 atm

benzene toluene

solution • solution •benzene benzene toluene toluene

• in ideal solution P (T)=X P (T) and P (T)=X P (T)

benzene benzene

benzene toluene

solution • solution solution • solutionbenzene bp toluene bp

• at boiling P + P = 1 atm

1 atm=X P (T )+(1-X )P (T )

benzene

solution solutionbp• for a given X solve for T

(or better have Mathematica solve equations)

( )lnsobp benzeneT X

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fractional distillation [Tbp vs (Xbenzene)vapor]

ln

ln

( )

( )

since 1

so solutionben ben bpvapor benzene

benzenetotal total

vapor so solutionbenzene ben ben bp

solutiontotal bp

solutionbp

X P TPX

P P

X X P T

P atm at T

get T from equations on previous slide

= =

=

=

( )vaporbp benzeneT X

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Chemistry 163BMulticomponent Phase Rule, Phase Diagram, Ideal Solutions, Osmosis

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Fractional Distilation

solution composition

vapor composition

I. • start with 50-50 mixture• Tbp ≈ 366

II. • vapor Xvbenzene ≈.72

III. • condense Xsolnbenzene ≈.72

• Tbp≈359.5

IV. • evaporate • vapor Xv

benzene ≈.88

V. etc, ...

VI. approachesXbenzene=1

I

II

III

IV

bottom of column (warmer)

top of column (cooler)

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fractional distillation

http://home.att.net/~cat6a/images/fuels_06.gif

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Vapor Diffusion Crystal Growth

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Vapor Diffusion Crystal Growth

http://science.nasa.gov/ssl/msad/pcg/#HARDWARE

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Osmotic Pressure Equilibrium

P0+ P0=

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Reverse Osmosis

http://www.zenon.com/image/resources/glossary/reverse_osmosis/normal_osmosis.jpg