13) of an object made of iron,
oxidation takes place and that spot
behaves as anode and we can write
the reaction
Anode: 2 Fe (s) ¾® 2 Fe2+ + 4 e– 
o
(Fe2+
/Fe)
E
 = – 0 44 V
Electrons released at anodic spot move through the metal and go
to another spot on the metal and reduce oxygen in the presence of H+
(which is believed to be available from H2CO3 formed due to dissolution
of carbon dioxide from air into water Hydrogen ion in water may also
be available due to dissolution of other acidic oxides from the
atmosphere) This spot behaves as cathode with the reaction
Cathode: O2(g) + 4 H+(aq) + 4 e– ¾® 2 H2O (l) 
o
|
|
+
2
2
H
O  
H O
=1