Kuliah 2f Kimia Kristal

8/11/2019 Kuliah 2f Kimia Kristal

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Lecture 6 (9/27/2006)Lecture 6 (9/27/2006)

Crystal ChemistryCrystal Chemistry

Part 5:Part 5:

Mineral ReactionsMineral ReactionsPhase Euili!rium/"ta!ilityPhase Euili!rium/"ta!ility

#ntro to Physical Chemistry#ntro to Physical Chemistry


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Mineral Reactions in #$neousMineral Reactions in #$neous

En%ironmentsEn%ironments


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Mineral Reactions in Metamor&hicMineral Reactions in Metamor&hic

En%ironmentsEn%ironments

0 200 '00 600 00

2

'

6

0

2

'

6

0

6

2

25

*

*7

'*

50

0

Con+itionsnot ,oun+in crust

-.ERML (C1-C-) ME-MRP.#"M

3R#LME-MRP.#"M

L4RE RE#1L

ME-MRP.#"M

.#.RE RE#1L ME-MRP.#"M

81E PR-#LMEL-#1

CRUSTALGEOTHERM

TEMPERATURE (centigrade )


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Role o, olatilesRole o, olatiles

(.(.22 ; C ; C22)) Catalys

retro$ra+e reactionsretro$ra+e reactions

Pro$ra+e/

Pro$ra+e/

7ehy+ratio

n

7ehy+ratio

n

Retro$ra+e

Retro$ra+e


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Mineral Reactions in 1earMineral Reactions in 1ear

sur,ace En%ironmentssur,ace En%ironments Chemical 4eatherin$Chemical 4eatherin$

con%ersion o, minerals into sim&le layere+con%ersion o, minerals into sim&le layere+

silicates (montmorillonite an+ =aolinite)silicates (montmorillonite an+ =aolinite) +esilici?cation+esilici?cation

+issolution o, cations (1a+issolution o, cations (1a@@A BA B@@A CaA Ca@@@@A M$A M$@@@@))

e$ B,els&ar @ aci+ic >ater Musco%ite @ silica @ Be$ B,els&ar @ aci+ic >ater Musco%ite @ silica @ B@@

Musco%ite @ aci+ic >ater Baolinite @ BMusco%ite @ aci+ic >ater Baolinite @ B@@


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Mineral Reactions in .i$hMineral Reactions in .i$h

Pressure En%ironmentsPressure En%ironments Con%ersion to hi$hCon%ersion to hi$h

+ensity &olymor&hs+ensity &olymor&hs

#ncrease in#ncrease inCoor+inationCoor+ination

1um!ers o, cation1um!ers o, cation

sitessites


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Mineral "ta!ility/Euili!riumMineral "ta!ility/Euili!rium

Phase "ta!ilityPhase "ta!ility+e?ne+ !y the state (soli+A+e?ne+ !y the state (soli+Aliui+A $as or %a&or) an+ internal structureliui+A $as or %a&or) an+ internal structureo, a com&ositionally homo$eneouso, a com&ositionally homo$eneoussu!stance un+er &articular eDternalsu!stance un+er &articular eDternalcon+itions o, &ressure an+ tem&eraturecon+itions o, &ressure an+ tem&erature

MineralMineralo, constant com&osition iso, constant com&osition isconsi+ere+ a soli+ &haseconsi+ere+ a soli+ &hase

Phase (or mineral) sta!ility is commonlyPhase (or mineral) sta!ility is commonly&ortraye+ on a&ortraye+ on a Pressure-em&erature PhasePressure-em&erature Phaseia$ramia$ram


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Phase ia$ramsPhase ia$ramsne Com&onent Multicom&onent

!ili i i +


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"ta!ilityA cti%ation Ener$y an+"ta!ilityA cti%ation Ener$y an+

Euili!riumEuili!rium

"ta!ility"ta!ilityo, a &hase (or mineral) is relate+ to its internalo, a &hase (or mineral) is relate+ to its internalener$yA >hich stri%es to !e as lo> as &ossi!le un+er theener$yA >hich stri%es to !e as lo> as &ossi!le un+er theeDternal con+itionseDternal con+itions

Metasta!ilityMetasta!ilityeDists in a &hase >hen its ener$y is hi$hereDists in a &hase >hen its ener$y is hi$herthan P- con+itions in+icate it shoul+ !ethan P- con+itions in+icate it shoul+ !e

cti%ation Ener$ycti%ation Ener$yis the ener$y necessary to &ush a &haseis the ener$y necessary to &ush a &hase

,rom its metasta!le state to its sta!le state,rom its metasta!le state to its sta!le state Euili!riumEuili!riumeDists >hen the &hase is at its lo>est ener$yeDists >hen the &hase is at its lo>est ener$y

le%el ,or the current P- con+itions (->o minerals that arele%el ,or the current P- con+itions (->o minerals that arereacti%e >ith one anotherA may !e ,oun+ to !e inreacti%e >ith one anotherA may !e ,oun+ to !e ineuili!rium at &articular P- con+itions >hich on &haseeuili!rium at &articular P- con+itions >hich on &hase+ia$rams are reco$ni


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Phase Com&onentPhase Com&onent

Com&onentsCom&onentsare the chemical entitiesare the chemical entitiesnecessary to +e?ne all the &otentialnecessary to +e?ne all the &otential&hases in a system o, interest&hases in a system o, interest


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-hermo+ynamics (P Chem)-hermo+ynamics (P Chem)

-heoretical !asis o, &hase euili!rium-heoretical !asis o, &hase euili!rium

-hree La>s o, -hermo+ynamics-hree La>s o, -hermo+ynamics

#nternal Ener$y (E)#nternal Ener$y (E) dE = dQ dWdE = dQ dW

QQG heat ener$yG heat ener$y

WWG >or= H I +ist H P I area I+ist H P I G >or= H I +ist H P I area I+ist H P I

at constant &ressure at constant &ressure dW = PdVdW = PdV

"oA"oA dE = dQ PdVdE = dQ PdV dV thera!dV thera!

e"#an$i%ne"#an$i%n


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"econ+ an+ -hir+ La>s o,"econ+ an+ -hir+ La>s o,

-hermo+ynamics-hermo+ynamics2 ll su!stances stri%e to !e at the2 ll su!stances stri%e to !e at the

$reatest state o, +isor+er (hi$hest$reatest state o, +isor+er (hi$hest

Entro&y"Entro&y") ,or a &articular - an+ P) ,or a &articular - an+ PdQ&T = dSdQ&T = dS

* t a!solute


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Relationshi& o, i!!s ree Ener$y toRelationshi& o, i!!s ree Ener$y to

Phase Euili!riumPhase Euili!rium


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Cla&eyron EuationCla&eyron Euation

e?nes the state o, euili!rium !et>eene?nes the state o, euili!rium !et>eenreactants an+ &ro+uct in terms o, " an+ reactants an+ &ro+uct in terms o, " an+

dGdGrr= V= VrrdP SdP SrrdTdT

dGdG##= V= V##dP SdP S##dTdT

at euili!rium:at euili!rium:VVrrdP SdP SrrdT = VdT = V##dP SdP S##dTdT

%r* (V%r* (V## VVrr) dP = (S) dP = (S## SSrr) dT) dT

%r* dP&dT =%r* dP&dT =++S &S &++VVThe $!%#e %, the e-.i!i/ri. c.r0e 1i!! /eThe $!%#e %, the e-.i!i/ri. c.r0e 1i!! /e

#%$iti0e i, S and V /%th decrea$e %r#%$iti0e i, S and V /%th decrea$e %rincrea$e 1ith increa$ed T and Pincrea$e 1ith increa$ed T and P


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Kuliah 2f Kimia Kristal

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