The chemistry of corrosion of iron is essentially an electrochemical phenomenon. Explain the reactions occurring during the corrosion of iron in the atmosphere.
Solution:
Corrosion of iron in the presence of atmospheric gases like CO2, O2 and moisture is an electrochemical process.
The reaction occurring at cathode and anode are as follows:
CO2 + H2O H2CO3 HCO3- + H+
At cathode: 1/2 O2 + H2O + 2e 2OH-
At anode: Fe Fe2+ + 2e
4Fe(OH)2 + O2 Fe2O3. H2O + 2H2O
(Brown)
Corrosion of iron in the presence of atmospheric gases like CO2, O2 and moisture is an electrochemical process.
The reaction occurring at cathode and anode are as follows:
CO2 + H2O H2CO3 HCO3- + H+
At cathode: 1/2 O2 + H2O + 2e 2OH-
At anode: Fe Fe2+ + 2e
4Fe(OH)2 + O2 Fe2O3. H2O + 2H2O
(Brown)