Standard electrochemical potential series – 3B Scientific Electrochemistry Kit User Manual
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Standard electrochemical potential series
Summary of some important theoretical standard electrochemical potentials:
Reducing agent
'
Oxidizing agent + n e
-
Standard potential
( in V )
Au
'
Au
+
+ e
-
+
1.70
Au
'
Au
3+
+ 3 e
-
+ 1.42
Pt
'
Pt
2+
+2 e
-
+ 1.20
Ag
'
Ag
+
+ e
-
+ 0.81
Fe
'
Fe
3+
+ e
-
+ 0.77
Cu
'
Cu
2+
+2 e
-
+ 0.34
Cu
+
'
Cu
2+
+ e
-
+ 0.15
H
2
'
2 H
+
+2 e
-
0.00
Cu
'
Cu
+
+ 3 e
-
-
0.036
Pb
'
Pb
2+
+2 e
-
- 0.12
Ni
'
Ni
2+
+2 e
-
-
0.23
Fe
'
Fe
2+
+2 e
-
- 0.44
Zn
'
Zn
2+
+2 e
-
- 0.76
Al
'
Al
3+
+ 3 e
-
- 1.66
Mg
'
Mg
2+
+2 e
-
- 2.37
K
'
K
+
+ e
-
- 2.92
Li
'
Li
+
+ e
-
-
3.02
Increasing concentration of Increasing concentration of
Oxidizing agent Reducing agent
Noble metals can be distinguished from less noble metals on the basis of the difference in voltage that is measured.
Noble metals have positive potentials and ignoble metals have negative potentials.
If zinc, not a noble metal, is assigned the potential 0, then the electropositivity of metals towards the most noble metals
can be shown in an overview such as the following, based on the differences in voltage:
Zn Fe Pb Ni Cu Ag
0 0,5 1,0 1,5
Increasingly electropositive (noble)