What happens during corrosion of a metal? State the electrochemical basis of corrosion of iron.
Corrosion slowly coats the surfaces of metallic objects with oxides or other salts of the metal.
Metal reacts with gases present in atmosphere to form surface compounds in corrosion. The electrochemical basis of corrosion of iron is as follows:
Iron in contact with the dissolved CO2 and O2 undergoes oxidation as follows: Fe → Fe2+ + 2e– E°oxidation = + 0.44 V The elctrons lost by iron are taken up by the H+ ions present on the surface of the metal which were produced by the dissociation of H2CO3 and H2O.
How would you determine the standard electrode potential of the system Mg2+/Mg?
Use standard hydrogen electrode as anode and Mg2+ | Mg as a cathode we can measure the standard electrodepotential of systemMg2+ | Mg. Standard hydrogen electrode, represented by Pt(s), H2(g) (1 atm) | H+ (aq) and dip the electrode of Magnesium wire in a 1M MgSO4 solution .The standard hydrogen electrode is always zero.