Unit I:Physical Chemistry 1.1 Chemical Thermodynamics-II
1.Free Energy Functions: Helmholtz Free Energy, Gibb's Free Energy, Variation of Gibb's free energy with Pressure and Temperature.
2. Gibbs-Helmholtz equation
3. Thermodynamics of Open System: Partial Molal Properties, Chemical Potential and its variation with Pressure and Temperature, Gibb's Duhem equation.
4. Concept of Fugacity and Activity
5. van't Hoff reaction isotherm and van't Hoff reaction isochore.
Chemical Thermodynamics-II , Semester 3, As per syllabus of the University of Mumbai
1. 3oth November 2020 Dr. Aqeela Sattar Qureshi , Royal College , Mira Road
CHEMICAL THERMODYNAMICS
Semester : III
PAPER 1 , UNIT - i
2. Chemical Thermodynamics
• Chemical Thermodynamics deals with the application
of the laws of thermodynamics to chemical system
• FREE ENERGY FUNCTIONS
• The concept of free energy gives the amount of
available energy to perform useful work
• The free energy change is used –
to predict the spontaneous nature of a chemical
process
to study physical and chemical equilibria
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
3. FREE ENERGY FUNCTIONS
• HELMHOLTZ FREE ENERGY (A)
• Introduced by German Physicist Hermann
von Helmholtz (1821-1894) to define
equilibrium at constant temeperature
• Symbol ‘A’ is taken from German word
‘Arbeit’ which means work
• Work function is defined as A = E – T S
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
4. HELMHOLTZ FREE ENERGY (A)
• Work function is defined as A = E – T S
• ‘A’ is an extensive property
• ‘’E’ and ‘S’ are state functions, independent of
history , mechanism, path etc so A is also a
state function
• For an isothermal change from state 1 to state 2
• A1 = E1 – T S1 and A2 = E2 – T S2
• A2 - A1 = E2 – T S2 - E1 + T S1
• Δ A = Δ E – T ΔS
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
5. HELMHOLTZ FREE ENERGY (A)
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
maxmax
rev
revrev
rev
rev
rev
WAorWA
workmaximumtoequalisassociated
work,reversiblyoutcarriedisprocessSince
WA
(3)and(2)equationComparing
qEWi.eWqE
micsthermodynaoflawfirstbyBut
(2)---qEA
(1)eqninngSubstituti
qST
T
q
S
etemperaturconstantatprocessreversibleaFor
(1)----STEA
)3(
Thus decrease
in Helmholtz
free energy
gives the
maximum
work that can
be done by
the system
6. GIBBS FREE ENERGY (G)
• Introduced by American Physicist J. W. Gibbs
(1839-1903) , it relates to net work done by the system
• Gibbs free energy is defined as G = H– T S
• ‘G’ is an extensive property
• ‘G’ is also a state function
• For an isothermal change from state 1 to state 2
• G1 = H1 – T S1 and G2 = H2 – T S2
• G2 - G1 = H2 – T S2 - H1 + T S1
• Δ G = Δ H – T ΔS
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
7. gibbs FREE ENERGY (g)
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
VPWG
(3)and(2)equationComparing
qEWi.eWqE
micsthermodynaoflawfirstbyBut
VPqEG
qVPEG
VPEHBut
qHG
(1)eqninngSubstituti
qST
T
q
S
etemperaturconstantatprocessreversibleaFor
(1)----STHG
rev
revrev
rev
rev
rev
rev
rev
)3(
)2(
8. gibbs FREE ENERGY (g)
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
netexpmaxexpmax
exp
maxmax
maxrev
rev
WWWWWG
VPWbygivenispressureconstant
againstgasofexpansiontoduedoneworkBut
VPWG-ORVPWG
WW
workmaximumtoequalisassociated
work,reversiblyoutcarriedisprocessSince
VPWG
)(
Thus decrease in Gibbs free energy gives the
net work that can be done by the system
9. Relation between Gibb’s free energy
and Helmholtz free energy
• Gibbs free energy change ∆G is given by,
∆G = ∆H – T∆S -- (1)
• Helmholtz free energy is given by ,
∆A =∆E – T∆S -- (2)
• But enthalpy change for a chemical reaction at constant
pressure is given by,
∆H = ∆E + P∆V --(3)
• Substituting (3) in equation (1) we get,
• ∆G = ∆E + P∆V – T∆S ie. ∆G = ∆E – T∆S + P∆V
• Since , ∆A = ∆E – T∆S
• from equation (2), we get ∆G = ∆A + P∆V
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
10. Significance of Gibb’s free energy
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
• The sign of ∆G helps to decide the
nature of process
∆G < 0 process is spontaneous
∆G > 0 process is non-spontaneous
∆G = 0 process has reached equilibrium
11. Variation of Gibb’s free energy
with temperature and pressure
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
• Gibb’s free energy is defined as G = H – TS - - (1)
• By definition H = E + PV
• Therefore G = E + PV – TS
•For infinitesimal change, equation (1) can be
written as, dG = dE + PdV + VdP – SdT - TdS --
(2)
• From the first law of thermodynamics,
dE = dq + dW
• If work is of expansion type, then dw = - PdV
• . . . dE = dq - PdV or dq= dE + PdV ---- (3)
12. Variation of Gibb’s free energy
with temperature and pressure
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
• According to definition of entropy
• dS= dqrev / T or dqrev = T.dS
where, dS is infinitesimal entropy change for a reversible
process substituting (3)
• TdS = dE + PdV --- (4)
• Substituting in eqn (2)
• dG = dE + PdV + VdP – SdT - TdS -- (2)
• dG = TdS + VdP – SdT - TdS
dG = VdP – S.dT ----- (5)
13. Variation of Gibb’s free energy
with temperature and pressure
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
The rate of change of
Gibb’s free energy with
temperature at constant
pressure is equal to
decrease in entropy of the
system.
The rate of change of
Gibb’s free energy with
respect to pressure at
constant temperature is
equal to increase in
volume occupied by the
system.
V
dP
dG
i.eVdPdG
0dT,etemperaturconstantAt
S
dT
dG
i.eSdT-dG
0dP,pressureconstantAt
SdTVdPdG
T
P
14. GIBB’S HELMHOLTZ EQUATION
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
dTSSSSdTGd(G
dT)(-S-dT-SdGdG
dTS-dGanddTS-dG
dTamountsmallbychangedisetemperaturwhen
energyfreeinchangesthebedGanddGLet
SdT-dG
0dP,pressureconstantAt
SdTVdPdG
asbe writtencanpressureandetemperatur
henergy witfreesGibb’ofVariation
122112
1212
2211
21
)()()
15. GIBB’S HELMHOLTZ EQUATION
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
(1)---S
dT
Gd
dTS-Gd
dTSSSSdTGd(G 122112
)()()
16. GIBB’S HELMHOLTZ EQUATION
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
change.energyfreeof
tcoefficieneTemperaturasknwonis
dT
Gd
termThe
equationHelmholtzGibbsasknownisequationAbove
dT
Gd
THG
(1)equationinS-ofvaluengSubstituti
S)T(-HGi.e
ST-HG
bygivenisenergyfreein
changeetemperaturcosnstantAt
P
P
17. GIBB’S HELMHOLTZ EQUATION
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
(1)---
dT
Gd
T
1
T
G
TG
dT
d
dT
Gd
T
1
T
GTG
dT
d
dT
Gd
T
1
T1
dT
d
GTG
dT
d
pressure.constantatetemperaturto
respectwith
T
G
atingdifferentibyobtainedis
equationHelmholtzGibbsofformAnother
P
P
P
2
2
1
18. GIBB’S HELMHOLTZ EQUATION
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
)2(
2
2
P
22
P
22
P
dT
Gd
T
1
T
H
T
G
dT
Gd
T
T
T
H
T
G
TbyequationaboveDividing
dT
Gd
THG
isequationHelmholtzGibbs
19. partial molal quantity
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
equationHelmholtzGibbs
offormanotherisequationaboveThe
T
H
TG
dT
d
T
H
T
G
T
G
TG
dT
d
(2)and(1)equationComparing
2
22
2
20. partial molal quantity
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
)
....,
i
n......,
3
n,
2
n,
1
n,P,T(fX
t.constituenvariousofamount
andpressuree,temperaturondependwillx''thenstudy
forselectedsystemofpropertyextensiveanyisx''If
ly.respectivei....3,2,1tsconstituen
ofmolesofno.thebe
i
n
3
n,
2
n
1
nLet
tconstituenithofconsistingsystemopenanConsider
21. partial molal quantity
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
i
....nn,P,nT,i
2
.....nn,P,nT,
1
.....nn,P,nT,
i
....nn,P,nT,i
2
.....nn,P,nT,
1
.....nn,P,nT,.,....n,nT,n.,....n,nP,n
dn
n
x
dn
n
x
dn
n
x
dx
Pressure,andeTemperaturconstantAt
dn
n
x
dn
n
x
dn
n
x
dP
P
x
dT
T
x
dx
asbe writtencandx''systemtheinchangesmallaFor
1)-i(31i31i32
1)-i(31i31
i32i21i21
in......,2n,1n,P,T(fX
.......
.......
21
2
1
)
22. partial molal quantity
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
system.ofncompositiothe
affectnotdoesmoleaddedthethatsystemofquantitylargeasuchtoadded
ispressureandetemperaturconstantatcomponentparticularofmole
onewhen...systemofvolume,enthalpyenergy,freeassuchpropertyin
changethegivesitthatisquantitymolarpartialofcesignificanphysicalThe
dnxdnxdnxdx
property.theofsymboltheoverbar
by writingdrepresenteisItquantity.molalpartialasknownis
n
x
termThe
dn
n
x
dn
n
x
dn
n
x
dx
ii21
i
....nn,P,nT,i
2
.....nn,P,nT,
1
.....nn,P,nT, 1)-i(31i31i32
......
....
21
21
23. partial molal volume
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
dnV........dnVdnVdV
dn
n
V
dn
n
V
dn
n
V
dV
,belvolume wilin
changesmallpressureandetemperaturconstantAt
volume.molalpartialasknownis
n
V
uantityq
thethenpropertyextensivetheisvolumeIf
ii2211
i
...n,nnP,T,2
2
...n,nnP,T,2
1
...n,nP,T,1
i31
i31i2
......
...
24. CHEMICAL POTENTIAL
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
dn........dndndG''by
drepresenteisandpotentialchemicalasknownalsoistI
.G)(energyfreemolalpartialasknownis
n
G
uantityq
dn
n
G
dn
n
G
dn
n
G
dG
,bellenergy wifreein
changesmallpressureandetemperaturconstantAt
)n.....n,n,n,P,T(fGei.
propertyextensiveanissystemaofenergyreeF
ii21
i
...n,nnP,T,2
2
...n,nnP,T,2
1
...n,nP,T,1
i321
i31
i31i2
21
......
...
25. gibbs duhemequation
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
dn........dndndG''by
drepresenteisandpotentialchemicalasknownalsoistI
.G)(energyfreemolalpartialasknownis
n
G
uantityq
dn
n
G
dn
n
G
dn
n
G
dG
,bellenergy wifreein
changesmallpressureandetemperaturconstantAt
)n.....n,n,n,P,T(fGei.
propertyextensiveanissystemaofenergyreeF
ii21
i
...n,nnP,T,2
2
...n,nnP,T,2
1
...n,nP,T,1
i321
i31
i31i2
21
......
...
27. gibbs duhem equation
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
21
21
21
21
21
0
0
0
)
d
n
n
d
dndn
dndn
isequationDuhemGibbsmixture
binaryaForon.distillatiassuchequilibrialiquid
-GasofstudytheinusefulisequationDuhemGibbs
dn
asbe writtenalsocanequationaboveThe
equation.DuhemGibbsasknownisequationaboveThe
dn....dndn
dn....dnd(ndGdG
1
2
21
21
ii
ii21
ii21
28. gibbs duhem equation
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
energy.freetoequalispotential
chemicalsubstancepureanyofmole1forThus
G,1nwhen
2)eqnN(G)bewill
equationDuhemGibbsthensubstancepurei.e
tconstituen1onlyofconsistssystemaIf
vedthenvedifi.etconstituen
2ndofpotentialchemicaltheaffectstconstituen1st
ofpotentialchemicalthatindicatesequationAbove
d
n
n
d
NP,T,
1
2
(
.21
21
29. 3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
V
dP
dG
i.eVdPdG
0dT,etemperaturconstantAt
S
dT
dG
i.eSdT-dG
0dP,pressureconstantAt
SdTVdPdG
T
P
Effect of temperature and
Pressure on chemical potential
30. 3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
iTi
iTi
i
T
dn
dV
dn
dG
Pd
d
dn
dV
dP
dG
nd
d
n'w.r.tequationaboveatingDifferenti
V
dP
dG
'
Effect ofPressureon chemical potential
i
i
V
Pd
d
31. 3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
iPi
iPi
i
P
dn
dS
dn
dG
Td
d
dn
dS
dT
dG
nd
d
n'w.r.tequationaboveatingDifferenti
S
dT
dG
'
Effect of temperature on chemicalpotential
i
i
S
Td
d
32. 3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
CONCEPT OF FUGACITY AND ACTIVITY
1
2
12
ln
ln 2
1
P
P
RTG
PRTGG
dP
P
RT
dGequation,abovegIntegratin
dP
P
RT
dG
P
RT
V,RTPV,gasidealanFor
VdPdGetemperaturconstantAt
SdT-VdPdGbygivenis
pressureandetemperaturhenergy witfreeofvariationThe
P
P
P
P
G
G
2
1
2
1
33. 3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
CONCEPT OF FUGACITY AND ACTIVITY
(2)---BlnfRTG
bygivenisfugacityandenergyfreebetweenrelationThe
'f'symbolthebydrepresenteisItsubstance.theof
tendencyescapingthemeasuretousedisfugacitytermThe
tendency.escapingas
knownispropertyThisstate.anotherintopasstotendencyhas
stategivenainsubstanceeverythatsuggestedHefugacity.
andactivityasknownparametersmicthermodynanewtwo
introducedLewisN.G.gasesrealforncalculatioenergyfree
explaintoorderIngases.idealforonlyvalidisEquation
P
P
RTG
)1(
)1(ln
1
2
34. 3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
CONCEPT OF FUGACITY AND ACTIVITY
)4(ln
lnln
ln
0
0
0
0
f
f
RTG-G
fRTfRTG-G
(2)equationfrom(3)equationgSubtractin
(3)---BfRTG
statestandardinfugacityandenergyfreethebefandGLet
condition.standardunderdonewasGoftsmeasuremenallHence
.calculatedbecannotBknown,notisGofvalueabsoluteSince
constantaisBwhere(2)---BlnfRTG
0
0
0
0
35. 3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
CONCEPT OF FUGACITY AND ACTIVITY
(6)--
a
a
RTG
aRTGaRTGGG
aRTGGandaRTGG
bewillstatestwothefor(5)equationthethena
andaareactivitieswhenenergiesfreeareGandGIf
GG1,aIf
aRTGG
state.standardtheinsubstance
sametheoffugacitytheatostategiventheinsubstance
theoffugacityofratiotheasdefinedisactivityThus
a'.'bydrepresenteisandactivityasknownis
f
f
ratioThe
00
12
0
2
0
1
2
121
0
0
1
2
12
21
0
ln
)ln()ln(
lnln
)5(ln
36. 3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
CONCEPT OF FUGACITY AND ACTIVITY
aRT
asbe writtencanaRTGGi.e(5)equation
Gand1nsubstance,ofmole1For
activity.byreplacedareionconcentrat
wheneverobtainedareresultexactmoreHencesolvent.
withsolutesofreactionsandattractionmutualthe
ionconsideratintotakeactivitiesthesolutionsofcaseIn
possible.becomenscalculatioexactpressureofplace
inusedareactivitieswhenThus,pressure.ofplacethe
takesactivitythatfoundisit(6)and(1)equationFrom
(6)--
a
a
RTGand(1)--
P
P
RTG
0
ln
ln
lnln
0
1
2
1
2
37. 3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
VAN’ T HOFF’S REACTION ISOTHERM
substance.indicatedofpotentialchemicalareswhere
bereactiontheinparttaking
substancesvariousofenergyfreemolalpartialtheLet
quantitymolalpartialoftermsinexressedbemustsystem
ofpropertymicthermodynachange,canncompositio
osemixture whaisionconsideratundersystemtheSince
.....mMLl....BbaA
reactiongeneraltheConsider
,M,L,B,A
'
.........
reactants.andproductofpressurespartialandG,G
betweenrelationthegivesisothermreactionHofftVan'
0
38. 3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
VAN’ T HOFF’S REACTION ISOTHERM
statestandard
insubstanceaofpotentialchemicaliswhere
aRT
realtionfollowingusignactivityoftermsinexpressedbe
canstateanyinsubstanceaofpotetntialchemicalThe
bamlG
GGGenergyfreeinChange
baG
mlG
bewillreactantsandproductofenergyFree
0
0
BAML
reactantproduct
BAreactant
MLproduct
)2(ln
)1(.....)(.....)(
.....
.....
39. 3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
VAN’ T HOFF’S REACTION ISOTHERM
state.standardtheirinarereactiontheininvolved
substancestheallnchange wheenergyfreeisGwhere
aa
aa
RTGG
aa
aa
RTbamlG
aRTbaRTa
aRTmaRTlG
belenergy wilfreeinchangethen(2)equation
fromderivedexpressioningcorrespondbyreplaced
are(1)equationinofvaluestheIf
0
b
B
a
A
m
M
l
L0
b
B
a
A
m
M
l
L
BAML
BBAA
MMLL
MLBA
)3(
....
....
ln
....
....
ln..)](..)[(
.....])ln()ln([
...])ln()ln([
..,,,
0000
00
00
40. 3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
VAN’ T HOFF’S REACTION ISOTHERM
state.standardforequationHofftVan'is(5)Equation
(5)---KpRTG
GmequilibriuatprocesschemicalaFor
isotherm.rxnHofftVan'asknwonare(4)and(3)Equation
(4)---KpRTGG
Kp
aa
aa
system
gaseousofcaseinandconstantmequilibriuasknownis
reactants&productofactivitiesofratioinvolvingtermThe
---
aa
aa
RTGG
0
0
b
B
a
A
m
M
l
L
b
B
a
A
m
M
l
L0
ln
0
ln
....
....
)3(
....
....
ln
41. 3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
VAN’ T HOFF’S REACTION isochore
T
KpT
R
T
G
T
KpRT
T
G
pressureconstantatetemperaturw.r.t(1)eqnatingDifferenti
(1)---KpRTG
isstatestandardforisothermHofftVan'
---
aa
aa
RTGG
P
0
P
0
0
b
B
a
A
m
M
l
L0
.ln
)ln(
ln
)3(
....
....
ln
equation.HelmholtzGibbsandisothermHofftvan'using
obtainedbecanrelationThee.temperaturandconstant
mequilibriubetweenrelationthegivesequationHofftVan'
42. 3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
VAN’ T HOFF’S REACTION isochore
KpRT
T
Kp
RT
T
G
T
TbyequationabovegMultiplyin
KpR
T
Kp
RT
T
G
Kp
T
Kp
TR
T
G
T
T
Kp
T
Kp
TR
T
G
T
KpT
R
T
G
P
0
P
0
P
0
P
0
P
0
ln
ln
ln
ln
.ln
ln
.ln
ln
.ln
2
43. 3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
VAN’ T HOFF’S REACTION isochore
)3(
)2(
ln
ln
ln
ln
2
2
00
P
0
P
0
00
0
P
0
0
P
0
HG
T
G
T
T
G
THG
isstatestandardforequationHelmholtzGibbs
G
T
Kp
RT
T
G
T
KpRTG(1)equationFrom
KpRT
T
Kp
RT
T
G
T
44. 3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
VAN’ T HOFF’S REACTION isochore
(5)--
RT
H
T
Kp
T
Kp
RTHhencenegligibleis
HandHbetweendifferencereactionchemicalaFor
state.stdtheirinaresubstancestheallhenpressure w
constantatreactionofenthalpyisHequationabovenI
T
Kp
RTH
G
T
Kp
RTHG
(3)and(2)equationEquating
0
0
0
000
2
2
2
2
ln
ln
)4(
ln
ln
45. 3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
VAN’ T HOFF’S REACTION isochore
21
12
1
2
21
12
2
2
303.2
ln
11
lnln
1
ln
.
1
ln
ln
2
1
2
2
1
2
TT
TT
R
H
Kp
Kp
TTR
H
KpKp
TR
H
Kp
T
TR
H
Kp
:equationHofftVan'ofnIntegratio
equation.HofftVan'asknowniseqnAbove
(5)--
RT
H
T
Kp
T
T
Kp
Kp
T
T
Kp
Kp
1
1
46. 3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
VAN’ T HOFF’S REACTION isochore
T
lnRTn
T
Kc
T
Kp
etemperaturw.r.tequtionaboveatingDifferenti
lnRTnlnKclnKp
equationaboveoflogTaking
.(RT)KcKp
equationfollowingusingbyobtainedbecanvolume
constantatreactionofheatinvolving(5)eqnofformotherThe
(5)--
RT
H
T
Kp
n
lnln
ln
2
47. 3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
VAN’ T HOFF’S REACTION isochore
)7(
ln
ln
ln
ln
)6(
lnln
lnln
2
2
2
2
RT
nRT-H
T
Kc
T
n
RT
H
T
Kc
RT
H
T
n
T
Kc
(5)--
RT
H
T
Kp
(5)eqnand(6)equationEquating
T
n
T
Kc
T
Kp
T
lnRTn
T
Kc
T
Kp
48. 3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
VAN’ T HOFF’S REACTION isochore
IsochoreHofftVan'or
equationHofftVan'asknownisequationaboveThe
RT
E
T
Kc
(7)equationinngSubstituti
EnRT-H
nRTEH
equation
followingthebyvolumeconstantatreactionofheat
torelatedispressureconstantatreactionofheatThe
RT
nRT-H
T
Kc
2
2
ln
)7(
ln
49. Reference Books :
• Advanced Physical chemistry – Gurdeep Raj
• Thermodynamics – A core course – 2nd edn by R.C.
Srivastava
• An introduction to chemical thermodynamics – 6th
edn Rastogi & Misra
• Advanced physical chemistry - D. N. Bajpai (S.
Chand )
3oth November 2020
Dr. Aqeela Sattar Qureshi , Royal College , Mira
Road
Recommended Reading :