??????S????? ?O?????O? ????? ??????S ??G?S????? ?????????S ??????S ????????? ?????? ???

1
??????S????? ?O?????O? ????? ??????S??G?S?????
?????????S ??????S????????? ?????? ???

• ?????µet??a

???????S ??????????S ???????O??S ??T?G???S
http//users.uoi.gr/mprodrom
2
??e?t????t???? te?????? a????s??
???taµµet????? te?????? ?as????ta? st??
pa?at???s? t?? s??s?? p?? s??d?e?
t?? ??tas? t??
?e?µat?? ?a? t?? efa?µ???µe?? t?s?
?at? t?
d????e?a µ?a? ??e?t????µ???? d?ad??as?a?
3
?????µet??a
??t? ?p? ???sµ??e? s?????e? e??a? d??at?? ?
??e?d?s? st?? ???d? ? ? a?a???? st?? ????d? ?a
s?µßa??e? ???????S???? se ??a s?stat??? t??
d?a??µat?? ? (?µµesa) µe t?? ap???e?st???
s?µµet??? e??? s?stat???? t??. ??te, ??a t?
s???e???µ??? a?t?d?as? a?a????? ? ??e?d?s?? ?
?????S? ??? ???????S ????? 100 ?a? se a?t?? t??
pe??pt?s? e??a? d??at? ?a s?s?et?s??µe t? ?e?µa
(?) p?? d?a???e? t? st???e?? ?at? t? d????e?a
?????? (t) t?? ??e?d?s?? ? t?? a?a????? µe t??
p?s?t?ta (m) t?? ?p? p??sd????sµ? ??s?a? µ???a???
ß????? (??). ? s?s??t?s? a?t? ???eta? µe t? ??µ?
t?? FARADAY.
4
??µ?? t?? Faraday
????????? ?S??????? ?????? ?S??????A
Q it ? Q?idt, t? f??t?? p?? d?a???e? t?
??e?t????t??? st???e?? (C A?s) m, t? ß???? t??
?p? p??sd????sµ? ??s?a? p?? ??e?d??eta? ?
a???eta? ?µesa ? ?µµesa µe ap?d?s? ?e?µat??
100 (g) MB, t? µ???a?? t?? ß???? (g/moL) n, ?
s???????? a???µ?? t?? ??e?t?????? p?? s?µµet?????
st?? a?t?d?as? ??e?d?s?? ? a?a?????
(eq/moL) F, ? sta?e?? t?? Faraday (96484,56 C/eq)
5
?????µet??a (?µes? ?a? ?µµes?)
???S? ??????????? ????S? ???????????
?µ?a?t?d?as? st? ??e?t??d?? e??as?a? ? ne- ? B G ne- ? ?
??t?d?as? st? d????µa ------ ? ? ? ? G
? p??sd??????µe?? ??s?a ? ??e?t????µ???
pa?a??µe?? ??s?a ap? t?? ???s? G
6
??p?? ?????µet????? te??????
?????µet??a µe e?e???µe?? d??aµ??? ??e?t??d???
(p?te?s??stat???) ?????µet??a µe sta?e?? ?e?µa ?
?????µet???? ????µ?t??s?
7
?????µet??a µe e?e???µe?? d??aµ???
?? d??aµ??? t?? ??e?t??d??? e??as?a? pa?aµ??e?
sta?e?? ?a? se a?t?? t?? t?µ? p?a?µat?p??e?ta?
p?s?t??? ?a? ap???e?st??? ? ??e?d?s? ? ? a?a????
t?? ?p? p??sd????sµ? ??s?a?.
8
?????µet??a µe sta?e?? ?e?µa
G??st? ?? ?????µet???? ????µ?t??s?, ?a?
p?a?µat?p??e?ta? µe d?aß?ßas? sta?e??? ?e?µat??
st? ?p??? ??e?d??eta? ? a???eta? p?s?t??? ?a?
ap???e?st??? ? ?p? p??sd????sµ? ??s?a.
9
?????µet???? ????µ?t??s?
??????da ?????????? ???t?p? d????µa
?????????? (de? apa?te?ta? t?t??d?t?s?) ?a??????t
?ta t?t??d?t? ????S? ???????S St??f???a
?????S ????????S ???????S/???????????
??????????
??p??? d?a??pt??
?????????? S??T???? ???????S
????????
10
?????µet???? ????µ?t??s?
11
?????µet???? ????µ?t??s? (ista?e??)
Fe2
??e?t??d?? e??as?a?
Fe3
H ??e?d?s? ???eta? ?at? t? d?aß?ßas? ?e?µat?? (i)
??a ????? (t). ??a QitmoLFe2Fn ?ta? ?µ??
Fe2 ???e? p??? µ???? ? ?pe?d??aµ??? a??d?? ?
ta?t?????? ??e?d?s? ?e??? (2H2O ? O2? 4H
4e-) ??at? ? pa?a???? f?sa??d?? ! ? ap?d?s?
?e?µat?? de? e??a? 100.
12
?????µet???? ????µ?t??s? (ista?e??)

• ????p???se??
• Ce3 se pe??sse?a
• ?a ??e?d??eta? se µ????te?? d??aµ??? ap? t? ?2?.
• To ??e?t????µ??? pa?a??µe?? Ce4 ?a
• a?t?d?? ta??tata µe t?? Fe2

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?????µet???? ????µ?t??s?
As3
? ??e?d?s? t?? apa?te? ????? ?pe?d??aµ???, st?
?p??? ?a e??aµe ??e?d?s? t?? ?2?.
??e?t??d?? e??as?a?
As5
14
?????µet???? ????µ?t??s?
I-
As3
??e?t??d?? e??as?a?
I20
As5

• S?ed?asµ?? pe???µat??
• St? ????st? d????µa p??st??eta? KI ?a? ?????
• To ??e?t????µ??? pa?a??µe?? ?2 a?t?d?? ta??tata
  µe t? As3, ??a ?atast??feta? e? t? ?e???s?a?
  (in situ)
• ?ta? ta As3 a?t?d??s??? p?s?t???, t?te t?
  ??e?t????µ??? pa?a??µe?? I2 ?a a?t?d??se? µe t?
  ?µ??? ?a? t? d????µa ?a ???µat?ste? ??t??a µp??.

15
?????µet???? ????µ?t??s?
(VitC)Red
? ??e?d?s? t?? apa?te? ????? ?pe?d??aµ???, st?
?p??? ?a e??aµe ??e?d?s? t?? ?2?.
??e?t??d?? e??as?a?
(VitC)Ox
I-
(VitC)Red
??e?t??d?? e??as?a?
I20
(VitC)Ox
3I-  ?  (?2?-) I3- 2e-

??e?t????µ??? ??e?d?s? (VitC)red I3-   ?
(VitC)ox 3I- 
??µ??? ??e?d?s?
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?????µet???? ????µ?t??s?

• ??e??e?t?µata
• ?e? apa?te?ta? t?t??d?t?s? p??t?p?? d?a??µat??
• ??a??et??? epa?a????µ?t?ta lt0,1, p??? ?a??
  a???ße?a
• ?????? a?t?µat?p???s?.
• Sf??µata
• ?ta? ? ap?d?s? ?e?µat?? lt 100
• ?a????sµ?? t?? te????? s?µe???

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?fa?µ???? ?????µet??a????sd????sµ??
?????e?e????, fa?????? µe Br2
Br-
18
?fa?µ???? ?????µet??a????sd????sµ?? ??????????
Cl-
Cl-
Cl-
Cl-
Cl-
Cl-
19
?a??de??µa
?at? t?? ?????µet???? p??sd????sµ? 50 mL
d?a??µat?? NaCl µe e?e???µe?? d??aµ???, µe ???d?
ap? ??????, ?ata?a?????a? 37,8 Coulombs. ?a
?p?????ste? ? ?a??????t?ta t?? d?a??µat?? NaCl.

• St?? ???d? p?a?µat?p??e?ta? ? ?µ?a?t?d?as?
  Ag ? Ag e-
• ?a? ta ??e?t????µ??? pa?a??µe?a ?g,
  a?t?d???? Ag Cl- ? AgCl
• Q/F NV ? N Q/FV 37,8 C / 96485 C/eq 0,05 L
  0,00784 eq/L

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?a??de??µa

• 50,0 mL d?a??µat?? Pb(NO3)2, ??e?t??????ta?, se
  ????? pe??ß?????,
• (a??d??? ??e?d?s? se PbO2) µe ?e?µa 0,750 ? ep?
  12,00 min.
• ?a ??af??? ?? ?µ?a?t?d??se?? se ???e ??e?t??d??
• ??sa g PbO2 ap?t??e?ta? st?? ???d?
• ???a a???s? ?f?sta?ta? ? ? ?at? t??
  ??e?t????s?

21
?a??de??µa
?at? t?? ?????µet???? p??sd????sµ? asp??????
(a?et???sa????????? ?????, ??180,15) se 50,00
mL de??µat?? µe ??e?t????t??? pa?a??µe?? ß??µ??
??e??st??e ?????? 3,15 min e?? ? ??tas? t??
?e?µat?? ?ta? 6,45 mA. Na ?p?????ste? ?
s?????t??s? t?? asp?????? se mg a?? ??t??
de??µat??.
St?? ???d? ????µe t?? pa?a???? ??e?t????µ???
pa?a??µe??? ß??µ??? s?µf??a µe t?? a?t?d?as?
2Br- ? Br2 2e- St? d????µa HOOCC6H4OCOCH3
3Br2 ? HOOCC6HBr3OCOCH3 3H 3Br-
22
S?????
?????µet??a ???? ?e?t?????a? ?p?d?s? ?e?µat??
100 ??µ?? Faraday ?µes? ?µµes?
?????µet??a ?????µet??a µe e?e???µe??
d??aµ??? ?????µet????? ????µet??se?? ?????µet?????
p??sd????sµ?? ?s3, VitC, Fe2 pa???s?a
Ce3 ??e??e?t?µata / ?e???e?t?µata ?????µet?????
????µet??se??