級(jí)物理化學(xué)4參考已雙語eng yxjwhk

Liquid-gasphasediagram(gas-phasemiscibleliquid-phasemiscibleliquid-phaseimmiscibleliquid-phasepartlymiscibleSolid-liquidphasediagram(liquidphasemiscible)Solid-phasemiscibleSolid-phaseSolid-phasepartlyGas-phasemiscibleandliquid-phaseGas-phasemiscibleandliquid-phase

Gas-phasemiscibleandliquid-phasepartlymisciblett*A

p=常 tBt

Lever

ppglklyy4y3 y2 y1????t?4???x5t2???x4x3xBx2x1ttttt tt x xB

xxA xxA ng

lk l

nl xg 杠桿規(guī)則適用于任何兩相平衡區(qū)(可在單相區(qū)和三相區(qū)附-20th§5-3.4.Phasediagramofsolid-liquidequilibriumofponentponentsolid-liquidequilibriumsystem:Liquid-phasemiscibleandsolid-phaseimmiscibleLiquid-phasemiscibleand aPartI.Systeminwhichnewcompoundhasnot aPartII.SysteminwhichnewcompoundhasStablecompound:thereisitselfmeltingpointinthephasediagram,forexample:CuCl(s)-FeCl3FeCl3H2

Au(s)-2Fe(s) CuCl2KClH2SO4H2OUnstablecompound:thereisnotitselfmeltingpointinthephasediagram.Thecompoundposesintoliquidandsolidphasebelowthetemperatureofmeltingpoint,for

CaF2-CaCl22KCl-CuCl

Au-SbK-(I)PhasediagramformingstableThediagrammayberegardedasthetwosimplephase ofcompleyimmisciblesystemofsolid.AddCuCl(A)orFeCl3(B)intoCompoundCthatresultsinthedescentofmeltingpointofcompoundC.Threekindsofhydratesareformed,H2SO44H2O(C1),H2SO42H2O(C2andH2SO4H2O(C3),theyhavethemselvesmelting(II)PhasediagramformingunstablecompoundCistheunstablecompoundconsistsofAB.IfcompoundCisheatedtilltotemperatureofOpoint,whichwillposeintoCaF2(A)andmeltingliquidwhosecomponentisN.O(s)

F(s)+N(l所以將O點(diǎn)的溫度稱為轉(zhuǎn)熔溫O(s)

F(s)+N(l) crystaliscoated(包晶現(xiàn)象)Lineb:Linea:Lined:

lA(s)lA(s)C(s)l(N)lA(s)lA(s)C(s)l(N)A(s)lA(s)lA(s)C(s)l(N)C(s)C(s)B(s)l(D)C(s)ToobtainpureC,maketheconcentrationofmeltingliquidisbetweenNDpoint,andtemperaturebetweentwothreephaseequilibriumLiquid-phasemiscibleandsolid-phaseLiquid-phasemiscibleandsolid-phasepartlyThreekindsofsolidSubstitutionsolidsolution:moleculesoratomsorionsofBsubstituteforthoseofCatrandomlocationsinthecrystalstructure.Itisthecompleymisciblesolidsolution.Defectsolidsolution:partlycrystallatticeinCissubstitutedbyotheratomsinB,andanotherpositionisempty.Interstitialsolidsolution:theBmoleculesoratoms(whichmustbesmall)occupyinterstices(holes)inthecrystalstructureofsubstanceCsolutionZn-Cu

Defectsolidsolution

solutionC-FeLiquid-phasemiscibleandsolidphasemiscibleCertainpairssubstancesformsolidsolutions.InasolidsolutionofBandC,therearenoindividualcrystalsofBandC.Instead,themoleculesoratomsorionsaremixedtogetheratthemolecularlevel,andthecompositionofthesolutioncanbevariedcontinuouslyoveracertainrange.Somepairsofsubstancesarecompleymiscibleinthesolidstate.ExampleincludeCu-Ni,Sb-Bi,KNO3-NaNO3Phasediagramofthecompleymisciblesysteminsolidphaseissimilartotheoneofthecompleymisciblesysteminliquidphase.Degreeofdomofponentatconstantpf*C 12 13Singlephasesolidsolution

f*C1211Twophaseregionswithliquid-solidin f*C1221PartI.Misciblesystemwithouthighestandlowestmeltingf*

Whensolids

f*f* yidealsolidsolution.

mayberaisedbythepresenceofthesecondNotethezingpointofAgisraised,andoneofAuAA1A2A3isthezingpointcurve,andBB1B2B3isthemeltingpointcurveysisthechangefromatoIfameltingliquidofCuandNiwithanycompositioniscooled(apoint),asolidsolutionbeginstozeoutatbpoint.ThesolidsolutionisricherinNithantheliquidsolution.Asthetwo-phasesystemofsolidplusmeltiscooledfurther,themolefractionofNidecreasesintheboththesolidsolutionandthemeltingliquid(frombtoc”thatcomponentofsolidphasedecreasealongcc’c”,andthatofliquidphasebb’b”).Eventually,asolidsolutionisformedthat(fromc″toe”)hasthesamecompositionasthemeltingliquidwasstartedwith.ZoneUltra-purificationofThetechniquemakesuseofthenon-equilibriumpropertiesofthesystem.Itreliesontheimpuritiesbeingmoresolubleinthemoltensamplethaninthesolid,andsweepsthemupbypassingamoltenzonerepeatedlyfromonendtotheotheralongasample.Thezoneattheendofthesampleisthedirtysolidwhichcanbediscarded.枝晶偏析：固相中分子運(yùn)動(dòng)緩慢，當(dāng)熔化物冷凝析出晶體時(shí)，固溶體不易與熔化物建立平衡。導(dǎo)致固相點(diǎn)滯后，液相點(diǎn)趕前。若降溫速度太快，體系來不及達(dá)到平衡，較早析出的晶體含高 組分較多，形成枝晶，后析出的晶體含低 分較多，填充在最早析出的枝晶的干枝之間，這種現(xiàn)象稱為枝晶偏由于“枝晶偏析”，使固相結(jié)構(gòu)不均勻，會(huì)影響合金的性能枝晶偏析。PartII.Misciblesystemwithhighestorlowestmeltingpoint yuniform,therearelargedeviationsfromideality,thesolid-liquidsphasediagrammayshowaminimumora zingpointofeachcompoundisdepressedbythepresenceoftheother(left zingpointofeachcompoundiselevatedbythepresenceoftheother(rightLiquid-phasemiscibleandsolidphasepartlyTheradiusofmolecules,oratoms,orionsofonesubstance,issmall,andtheycanoccupyintersticesofothersubstancetoformpartlymisciblesysteminlocalextent. PartI.solid-phasepartlymisciblewiththelowestmeltingAboveofAEBcurve:leftofAJF:solidsolutionrightofBCG:solidsolutionThreetwo-phaseAEJ:l+BEC:l+FJECG:(1)+AEandBEare zingcurveofsolidsolutions,andAJandBCaremeltingcurveofsolidsolutionsJECisthree-phaselineinequilibrium,(1)+l+EisEislowestmeltingpointof(1)andCoolingcurveofa(f*=b(f*=d(f*=

a:lb:l+(1)d:(1)+l(f*=Coolingcurveofe:lf:l+(1)(1)+l(1)(1)+e(f*=f(f*=(f*=(f*=(f*=Coolingcurveofj:lk:l+(1)(1) l+(2)(1)+j(f*=k(f*=(f*=(f*=PartII.solid-phasepartlymisciblewiththeperitecticThreesingle-phaseregions:leftofBCAcurve:(l)ADF:solidsolution(1)rightofBEG:solidsolutionThreetwo-phaseregions:BCE:l+(2)ACD:l+FDEG:(1)+CDEisthree-phaselineinequilibrium,l+(1)+(2). zingpointcurveHeatingfromatoCDEl+(1)l+(1)+l+(2)D(solidsolution1) E(solidsolution2)C(meltingThetemperatureofCDElineiscalledasperitecticEvolvementandcombinationofphasediagramofponentsystem ySeephasediagram

partly yWhenAandBis yimmiscible,bchangeWhenmiscibilityaugments,twosolidsolutionsgraduallycloseup,eventuallybchangec.(4).Evolvementandcombinationofphasediagramofponentsystem l壓 壓

s1 將相圖c看成是相圖ab中上下兩個(gè)簡(jiǎn)單相圖組合而成的。由s1既能s2又能與l平衡，因此組合時(shí)出現(xiàn)s1，s2與l三相平衡情況。相圖的解已知863K4.4×106Pa時(shí)，固體紅磷、液體于平

s(紅磷 處于平衡；s(紅磷) ③黑磷、紅磷和液態(tài)磷的密度2.70×103kgm2.34×103kgm3，1.81×103kgm

m T根據(jù)以上數(shù)據(jù)問黑磷和紅磷 隨壓力怎樣變化黑磷Hm

sHm

紅2.34×103kg·m-l1.81×103kg·m- sHm

V黑

紅

mT (863K，4.4×106Pa)，s(紅磷 (923K，1.0×107Pa)，s(紅磷 s(黑磷 A，B二組分在液態(tài)完全互溶，已知液體B在80℃下蒸氣壓101.325 kPa。組分A的正常沸點(diǎn)比組分B的正常沸點(diǎn)高10℃。在101.325 kPa將8mol A和2mol B混合加熱到60℃產(chǎn) 氣泡，其組成為yB=0.6。畫出此二組分系統(tǒng)在101.325kPa并標(biāo)出各相區(qū) 8molB和2molA的混合物在101.325kPa，65℃時(shí)，B見右當(dāng)8molA和2molB混合加熱x總(0.2xB0.1)<x總即：氣相線在液相線當(dāng)7molB和3molA混合冷卻yB(0.6)<x總xB(0.9)>x總即：液相線在氣相線①zBxB

8 0.90.8 0.9

n(gn(總（82）mol ②因圖中有恒沸點(diǎn)，單純用精溜方法只能得到純B混合物而不能得到純A molmolkJmol-1，與溫度無關(guān)，蒸氣看作理想氣體，液體體積可以忽略不計(jì) 解

A p*A 其中p 101.325kPa97.7kPa3.63 MA=18.02gmol-1，MB=123.11gmol- A 18.02g A B 123.11g 3.63B

wA 3.94wB2用克–克方

40.7103kJmol1 ln 101.325kPa 8.314JK1 373 368K 84.8Ap(總p*B+84.8kPa=99.2化合物的蒸氣壓為B

=14.4wA w

M M

18.02gmol184.8 14.4 求得:1

wA

gmol4.A，B二組分液態(tài)部分互溶體系標(biāo)明各將14.4kg純A液體和9.6kg純B液體混合后加熱，當(dāng)溫度t無限接近t1(t=t1-dt)時(shí)(t1為三相共存溫度，

g+g+ltt1(t=t1+dt)時(shí)有哪幾個(gè)相平衡共存？

解：(1相區(qū)①：g(A+B)；②：l1(A+B)；③：g④：g ⑤：l2(A+B)；⑥：l1+l2（2）系統(tǒng)總量為M=mA+mB=(14.4+9.6)kg=24 9.6 當(dāng)t=t1-dt時(shí)，物系點(diǎn)在⑥區(qū)，液相共存，設(shè)混合物中l(wèi)1的質(zhì)量mA’，l2的質(zhì)量為mB’，由杠桿規(guī)則mA’(0.40－0.20)=mB’(0.80－0.40)，且mA’=16 mB’=8

＋

＝24當(dāng)t=t1+dt時(shí)，物系點(diǎn)在③區(qū)，有兩液相共存mA”(0.40－0.20)=mB”(0.60－0.40)，且mA”＋則氣、液兩相質(zhì)量各為12kg

＝24 如圖所示，在101.325kPa下，A，B二組分液態(tài)完全互溶，固態(tài)完全不互溶，其低共熔混合物wB= 0.40溶液180g，試回答 冷卻時(shí)，最多可得多 解：(1)從圖中可知，