Zn2 (aq) 2e- ? Zn(s)E0= ?0.76 V - PowerPoint PPT Presentation

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Zn2 (aq) 2e- ? Zn(s)E0= ?0.76 V

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Title: PowerPoint Presentation Author: Gil Last modified by: MOCHO Created Date: 11/15/2004 8:30:30 AM Document presentation format: On-screen Show – PowerPoint PPT presentation

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Title: Zn2 (aq) 2e- ? Zn(s)E0= ?0.76 V


1
?? ??????????-?????
??? ???? ???
  1. Zn2(aq) 2e- ? Zn(s) E0 ?0.76 V
  2. Cu2(aq) 2e- ? Cu(s) E0 0.34 V

????? ???? ???? ??? ????????? ?????? ????
  1. Zn(s) ? Zn2(aq) 2e- E0 0.76 V
  2. Cu2(aq) 2e- ? Cu(s) E0 0.34 V

Zn(s) Cu2(aq) ? Zn2(aq) Cu(s) E0 1.10 V
???? ????? ???
Zn / Zn2(aq) // Cu2(aq) / Cu
?????? ?????
2
???????? ?????????????
  • ????? ?????? ???????? ????? ???? (???? ?? ????
    ???) ???????? ????????? ????????? ?????
  • ???????? ?????? ??????, ?????? ????? ???? (??
    ??????? ?? "?? ????"). ???? ????????? ???
    ?????????? ????? ??????? ?? ???.
  • ?? ??? ????? ???? ??? ??????? ?? ?????? ??
    ??????? ????? ?? ?? ???? ??? ??????????.

?????? ????????
A1
Burette
Voltmeter
InE
RE
A2
B2
B1
???? ?????? ???????????!
3
Oxidizing Agent Reducing
Agent Reduction Potential(v) Li
e- ? Li -3.04 Na
e- ? Na -2.71 Mg2
2e- ? Mg -2.38 Al3
3e- ? Al -1.66 2H2O(l)
2e- ? H2(g) 2OH - -0.83
Zn2 2e- ? Zn -0.76 Cr3
3e- ? Cr -0.74 Fe2
2e- ? Fe -0.41 Cd2
2e- ? Cd -0.40 Ni2
2e- ? Ni -0.23 Sn2 2e-
? Sn -0.14 Pb2 2e- ?
Pb -0.13 Fe3 3e- ? Fe
-0.04 2H e- ? H2
-0.00 Sn4 2e- ? Sn2
0.15 Cu2 e- ? Cu
0.16 Cu2 2e- ? Cu
0.34 I2(s) 2e- ? 2I-
0.54 Fe3 e- ? Fe2
0.77 Ag e- ? Ag
0.80 Hg2 2e- ? Hg
0.85 ClO- H2O 2e- ?
Cl- 2OH- 0.90 NO3- 4H
3e- ? NO 2H2O 0.96 Br2
2e- ? 2Br- 1.07 O2
4H 4e- ? 2H2O 1.23
Cr2O7-2 14H 6e- ? 2Cr3
7H2O 1.33 Cl2 2e- ?
2Cl- 1.36 MnO4-2 8H 5e- ?
Mn2 4H2O 1.49 F2
2e- ? 2F- 2.87
????????? ?????
????? ????????? T25?C, 1 atm, 1M
4
???????? ?????
  • AgCl(s) e- ?Ag(s) Cl-(aq) E 0.222V
  • ?? ?? ?????? ?????
  • E 0.222 0.059?log Cl-
  • ????? ????? ????????? ????? ?????? ???? ????? ??
    ???????? ????!
  • Calomel Hg2Cl2(s) 2e- ?2Hg(l) 2Cl- E
    0.268V
  • ?????? ????? ???? ??? ?????? ???? ??? ?????????
    ???? ?????? ??????? ???? ?????????

5
???????? ?????????
  • ???????? ?????????
  • ???? ?????? ???? ??????-?????, ????' ???????
    (??????, ???, ???) ???????? ????? ???? ??
    ?????/??? ???? ??? ????? ?????? ????? ?????
  • ?????? ???????? (??????) (Rgt 1012 Ohm) ????? ????
    ???????? ??? ???? ?????? ??, ????? ?????? ??????
    ???????? ??????? ?????? ?????? pH. ????????
    ?????? ?????? ?? ????? ??????? (????????) ???
    ??????? ???? ?????? ???? ??? ???????
  • E E- 0.059logH E 0.059pH

6
???????? ??????
Ag/AgCl(s),Cl-(aq),H(aq)/glass/test
soln.//Cl-(aq),AgCl(s)/Ag
7
?????
  • ????? ????? ???? ?"? ??????? ?? ???????
  • ????? ???????-????? ??????
  • 1. Ox Fe2 ? Fe3 e- E
    ?0.771V
  • 2. Red Cr2O72- 14H 6e- ? 2Cr3 7H2O
    E1.232V
  • Cr2O72- 14H 6Fe2 ? 2Cr3 7H2O 6Fe3
    E1.232-0.7710.461V

Experimental Setup
?????
K2Cr2O7
Multimeter
Burette
Ag (s)
Pt (s)
AgCl (s)
FeSO4
HCl (aq)
8
2
1
(??? ????? K2Cr2O7 ???????)
K2Cr2O7 ????? ?????
Fe2
1 Fe3 e- ? Fe2 E0.771 V
AgCl e- ? Ag Cl- E0.222 V Fe3 Ag
Cl- ? Fe2 AgCl E0.549 V
2 Cr2O72- 14H 6e- ? 2Cr3 7H2O E1.232
V AgCl e- ? Ag Cl- E0.222 V
Cr2O72- Ag Cl- ? Cr3 AgCl
E01.010 V
9
  • ???????? ?????? ?"? ????? ????? ???????? ?? ???
    ????? ????? ???-???? ???? ?????? ?? ??????
    ???????? ?????? Ag/AgCl ????????? ?????? ??????
    ???????? ????????? ???? ?? ?????? ??? ???? ???
    ??"?.
  • ???? ????????? ?????? ???????? ?"? ?????? ?????
    ????? (????? ???? ???????? ????)
  • ???? ???' ??????????? ?????????? ??? ???
    ???????? ?????? ?????? ???????????? ????? ?????
    ???? ???? ?????
  • ???? ??' ?????????? ???? ?"? ?????? ????? ?????
    ?????.

10
?????? ???????????
??? ???? ??? ?????? ???? ?? ???????? ?????? ????
?????? ???? ???
????? ? 6 ?? ??????? ??????? ????? ?? ?????
?????? ???????????, ??? ???? ????? ??????
???????? ??????
Cr2O72- 14H 6Fe2 ? 2Cr3 7H2O 6Fe3
????? ???? ??????
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