Primary Conception of Chemical

1
??? ??????? Chapter 2 Primary Conception of
Chemical Thermodynamics
2
(No Transcript)
3
????????????????????????????????,????????????????
??????????????????????????????????????????
??????????????
????????????
????????????,?????????,????????
???????????,??????,????????
4
????
??? ???????????
??? ???????
??? ???????????
5
??????
1 ????????????????????????????????????????????????
???????????????????????????
2 ?????????????????????????
3 ??????????,??????????????????????
4 ???????????Gibbs????,??????????????????????
6
5 ????????????????????????????????????
6 ??????????????????????,??????????????????
7 ????????????????,????????????
8 ??????????????????????????
7
?? ???????,????????,?????????????????????????????
?????????????,??????
?? ????????,????????,?????????????????? ?????????
???
8
??? ???????
1 ???? 1.1?????(system and environment) 1.2
???????(state and state function) 1.3 ???(heat
and work) 1.4 ????(??) (thermodynamic energy)
9
1.1????? (system and environment)
??-----??????????????
??-----?????????????????
????(open system) ??????????????
? ?
????(closed system) ?????????????
????(isolated system) ???????????
10
1.2 ???????(state and state function)
??-----??????????????????????,???????????,????????
??????????????????????
????-----??????????,? p,V,T ??
11
??????????
(1) ????,???????
(2) ????,?????????,??????????????????,?????????
? ?????????,?????????
???????,???????,???????,????????
12
?????
???????????,??????
???????
n?V?U?H?S?G
???????????,???????
?????
T?P?M
13
1.3 ??? (heat and work)
?(Q)??????????????????????? ???????? ?????? Q
gt0,???? Q lt0??????
H2(g) ½ O2(g) H2O(g),??214.8 kJmol-1
?? ??,Q - 214.8 kJmol-1
?? ??,Q 214.8 kJmol-1
14
?-----??????,?????????????????????????W??,???????
????
???(???????) P??V
?
????(????????)???????
????????? (Wgt0),????????? (Wlt0)? ???????,????????,
???????????????
????????????,?????
15
1.4 ????(??)(thermodynamic energy)
????(U) ????????????????,?????????,???????????(t
otal capacity)???????????????????????U
?????,???????????????,???????? ?????????,??????U?
?????? ???? ????? U2 -U1 ?U ????

16
2 ???????(thermodynamic first law)
????????????????
??????-----??????????????,??????????,????????????
???,?????????????,????????????????
17
????,?????????,?????????????,?????????U
??????????????????????????,????,??????????Q,??????
??W?????????,??????????U U2-U1????????????Q
,????????W?
18
?????Q
?
?
?????W
U1
U2
U2 U1Q W
???????
?U U2- U1 Q W
??????????????
?U Q W
???W??????????(W')
19
??2????A??B?,??????100J,??50J???????A??????B????80
J,?Q?
B?-70J
A?70J
D?-30J
C?30J
v
20
?????????????,??????,???????,?????????????,???????
?????,???U ?Q ?W????????
???
? ?????
? ???????
? ?????????
? ???????(??????????)
? ???????????????????????????????
21
? ??????? Qgt0,W0, ?Ugt0 ? ???????Wlt0,????Q
lt0,?????????,???Ugt0? ? ??????,Q0
,?????????????Wlt0, ?UQ-W, ?Ugt0 ?
???????,Q0,?????Wgt0,???Ult0 ? ????Q0,W0, ?U0
22
3 ???????? (heat of reaction and enthalpy)
?????,???????????????,???????????????????
3.1 ???(Qv) ?????????????? ? ?V
0,W 0 ?U Q W Qv
23
3.2 ???(Qp) ????????????????,?????????????????????
???(P?P?P?)????
?U Q - P?V QP P ?V
QP ?UP?V
24
QP U2 PV2 - U1 - PV1 ( U2 PV2 )
(U1 PV1)
?(Enthalpy)
H U PV
????? QP H2 -H1 ?H
??????????,?????????????,???????????????????
?????H gt0,?????H lt 0?
25
4 ????(extent of reaction )
???? aA bB mC nD
?A-a
?B-b
?Cm
?Dn
??????????????????1mol????????????????????????????
????????????????
26
5 ?????? (thermochemical equation)
(1) ?????? ?????????????????????
?
???298.15K?100kPa?,??????1mol?(2mol H2(g)?1mol
O2(g)??,??2molH2O(g)?),??483.64kJ???
27
??
1.????????????
2.???????????
3.????,???????, ?rHm???
4.??????Qp??????, ?????
HgO(s) ?Hg(l) O2(g) ?rHm ? 90.83 kJmol-1
Hg(l) O2(g) ?HgO(s) ?rHm ? -90.83 kJmol-1
28
???rHm ???????????????,????mol-1?????????????
?????
????
????
??????
29
(2)??????? ????????????????,???????????????
?? T,p pº100kPa
??,?? T, p pº100kPa ,???
?? T,p pº100kPa ,c 1mol L-1
30
6 ??????
????????????????,????H ???????
? Hess?? (Hess law) ??????,??????????????,??????
???
31
??Hess??????????????,????????????????????
32
???????????????? C O2 CO2
?H1-393.4 KJmol-1 (1)   CO 1/2O2 CO2
?H2-283.0 KJmol-1 (2) ????????????
C 1/2O2 CO ?H3 ?
(3)
?????? ?H1?H2?H3 ?? ?H3 ?H1-
?H2 -393.40-(-283.0) -110.4
KJmol-1
33
? ??????? ??? T ?,?????????????1mol???????????????
??????????????????????????????fHm??? ?
34
(No Transcript)
35
???? cC dD yY zZ
(?????????T????)
?rHm? y?fHm ?(Y) z?fHm ?(Z) - c?fHm
?(C) d?fHm ?(D)
? ????????,???????
36
???fHm ?(CuO,s)?
? (2)?23? ,2CuO(s)2Cu(s)?2Cu2O(s)
(?rHm ?)32(?rHm ?)2 -22.6 kJmol-1
(3)?(1)?4? , 2Cu(s)O2(g)?2CuO(s)
(?rHm ?)4(?rHm ?)3(?rHm ?)1 - 314.6 kJmol-1
37
???????????????????????????,?????????????,??????
?????????????????,??19????Berthelot?Thomson???????
???????????,???,????,??????,? ??????????????????,?
???????????????????????????????????
38
???????????r H lt 0 ?????????
?rHgt 0 ?????????? ??,????????????????????,???????
???????????!
39
??? ??????? (spontaneous process and
entropy)
1 ???? (spontaneous process )
??????????,??????????????
2 ???????
? ????
? ???????,????????????
? ???
40
3 ????(entropy and entropy changes)
(1) ???(randomness)
NH4Cl???NH4 ?Cl- ??????????NH4C1???????,??????(?a
q??)????????NH4Cl???,???NH4(aq)?Cl-(aq)?????,????
???? NH4C1 ?????????
41
????????????????,??????????????????,???????? ????
??????????????????????????????????????????????????
??
??????????????????????????????????????,???????????
???????
42
(2) ????(entropy and entropy changes)
1877????????L.Bo1tzman??,????????????????????(e
ntropy)???
S k ln? S---?,k--- Boltzman?? ?-----?????(???????
) ?????????,?????J K-1 mol-1 ?
43
??????????????????????,???S,????????,????
??????,?????????????,???????
44
? ??????????? (the third law of thermodynamics
standard entropy)
???????????????(???T?P?n),?????????????
????????
?0 K?,??????????,??????????????????????????? 0
K??????????????S?(0 K)???????????????????
45
??????
?????298.15K?,1mol???????????????,Sm?,???Jmol-1
K-1?
46
4 ?????? (the entropy changes of chemical
reaction )
????????????? (?rSm?)????????????,????????????Hess
??,???????,????298.15K????????????
???????,??????,?????????????,?????????????????????
???????????????
??,?????????????????,????????????????????
47
???????????????????????
? ??????????S???
O2(g)? 2O(g)
C(s)H2O(g)CO(g)H2(g)
???298K?101.3kPa?,???????
HCl(g)NH3(g)NH4Cl(s)?
?rSm?94.6-186.8-192.3-284.5(J K-1 mol-1 )
48
?rSm?lt0,??????????? ?S? (?S?? ?S??)gt0 ?S?gt0
???? ?S?lt0 ????? ?S?0 ????
?Sgt0?????,?????????????????????????????,??????????
???????????
?S (?)?S(?) ?S(?)
????
?S (?)gt0 ????
49
??????????(Clausius)??????????????????????????????
????????????????????????????????????????
50
5 ?????????????? (Gibbs free energy, G which is
related to spontaneity)
(1) Gibbs??????
1902???????J.W,Gibbs???????,??????????Gibbs???(Gi
bbs freenergy),???G,?? kJ.mol-1?

?? ????????? GH-TS
51
?GG2-G1(H2-TS2)-(H1-TS1) ?H-T?S
?G G2-G1
lt0 ?????????????????,????????????????(G)????????
?G 0 ?,???G??????,????????????????????
????? ?G??H ? -T?S ?
?G lt 0( ?G? lt0)????
?Ggt 0 ( ?G ? gt 0) ?????,????
?G 0 ????
52
(3) ??????
???????Gibbs?? (the standard free energy of molar
formation)
????? P?101 kPa?,????????1mol?????????????????,??
???????????Gibbs????????fGm???
???????????????????????
?????????????
53
??????298K??????r Gm??
? 2NH3(g)N2(g)3H2(g)
? Fe2O3(s)13CO(g)2Fe(CO)53CO2
?
? ?r Gm? -2?fGm?(NH3)32.96 kJmol-1
??r Gm? 2?fGm?(Fe(CO)5)3?fGm?(CO2) -?fGm?(Fe2O3)
-13?fGm?(CO) -48.94 kJmol-1
54
????-????(Gibbs-Helmhltz)??
?rGm??rHm ? -T?rSm ?
????rHm ? ??rSm ??????,298K???????????,??rGm??????
?????
??
?rGm?(T)?rHm ? (298)-T?rSm ?(298)
?rGm??????????????
55
???????????
???? ? ? ? ? ? ? ????
???? ?rHm ?rSm ?rGm ????
1 - - ??????? ????
2 - ??????? ?????
3 ??()??(-) ?????????????????
4 - - ??(-)??() ?????????????????
56
(4 )??????
????????
????298.15K?????,?? CaCO3(s)?CaO(s)CO2(g)???????
???
? CaCO3(s)? CaO(s) CO2(g)
??(1)
?fGm ? /(kJmol-1) -1128.79 -604.03 -394.359
?rGm??fGm ?(CaO)?fGm ?(CO2)-?fGm ?(CaCO3)
(-604.03)(-394.359)-(-1128.79)
kJmol-1 130.40 kJmol-1gt0
298.15K?????,??????????
57
CaCO3(s)?CaO(s) CO2(g)
??(2)
?fHm?/(kJmol-1) -1206.92 -635.09
-393.509
Sm ? /(Jmol-1K-1) 92.9 39.75
213.74
?rHm ? ?fHm ?(CaO)?fHm ?(CO2)-?fHm ?(CaCO3)
(-635.09)(-393.509)-(-1206.92)
kJmol-1 178.32 kJmol-1
?rSm ? Sm ?(CaO)Sm ?(CO2)-Sm ?(CaCO3)
(39.75213.74)92.9 Jmol-1K-1 106.6
Jmol-1K-1
?rGm ?(298.15K)?rHm ?(298.15K)-T?rSm ?(298.15K)
?rGm ? 178.32-298.15106.610-3 kJmol-1
130.4 kJmol-1gt0
298.15K?????,???????????
58
?????2CuCl2(s)?2CuCl(s)Cl2(g)?298K,101.3kPa??????
?,?????????,?????298K?( )
B
A ?rHm? lt0
B ?rHm? gt0
C ?rSm?lt0
D ?rGm? lt0
?????????????????rGm? ???
(1)NH3(g)HCl(g)NH4Cl(s) ?rHm? lt0
(2)2Cl2O7(l)2Cl2(g)7 O2(g) ?rHm? lt0
(3)MgCl2(s)Mg(s)Cl2(g) ?rHm? gt0
59
??? ???????????
1 ??????? ???G????????????????????,????????????,?
??????????????????????????,???????????????????????
,?????????????????,???????????????,??????????????
?????????????????????
60
????????? ?????,????????????,?????????
???????
?????????????????
? ?rG0
? ???? v?v??0
? ???,???,????
? ?????(??)??,?????????
61
2 ??????(K?) (standard equilibrium constant)
(1) ????????? ??????
aA bB m C nD
c ?1.0 moldm-3
P ?100 kPa
K???????
62
?????????
? ???????????????????
? ??????????????????1?
? ???????????,??????1 ???????????????????????????
? ?????????????????
???????????????????,????????????,?????????????,???
???????????
63
3 ?????Gibbs??????? vant Hoff???
Gibbs?????G????????????????????????????(G?????),??
??????????,???????????????????????,?????G???,?????
??????????? ???????T?,??????GT???????GT???????van
t Hoff??????(???????????),??????vant
Hoff?????????(?????????????????)?
64
?rGm?????????? ?rGm?????????? Q???(???)?????????
????????
??rGm 0 ?
?G?0 ???? ?G0 ???? ?G?0 ???
QltK ? ???? QK ? ???? QgtK ?
???
65
??,T 298 K?,?????
?Gr?298 2?G?f NH3(g)- ?G?f N2(g)-3?G?f H2(g) -
33 kJmol-1 ?-?GT? 2.30RT lg K???, K?
6.2 105 (298 K) 298K??G????,???????????????? K
???,??????,??????????????,K????????????
66
4 ??????? ????????????????????????????????????????
?,???????????,????????????? ?????????????????????
???????????,????????????
67
(1) ?????????? ??????,??????K?????????????,????Q??
??????????????????????G????,??????????????????Q/
K????????????????? ????,???????????????QltK?,??????
??????,??????????????? QgtK? ,???????????
68
(2) ?????????? ???????????????????????????????????
????????? aA(g) bB(g) m C(g) nD(g)
????,???????n?
69
?n gt1?,?? gt0,Qp? gtKp ? ,??????
?n gt1?,?? lt0,Qp? ltKp ? ,??????
?n lt1?,?? gt0,Qp? ltKp ? ,??????
?n lt1?,?? lt0,Qp? gtKp ? ,??????
????,????????????????????????????????????????????
?
????????,????,??????,????????????????
70
(3)??????????
?rGm ? ?rHm ? -T?rSm ?
?????
?rHm ?gt0?,T2 gtT1 , K2 gtK1T2 lt T1 ,K2 lt K1
?rHm ? lt0?, T2 gtT1 , K2 lt K1 T2 lt T1 , K2 gtK1
??????,???????
????,????????
71
??????
????????????????,???????????????????????????(????
?????),???????????????????????????
?? ?????????????????,???????????
?????????????,???????????
72
??
1 ??????????
2 ???????????
3 ?????