Please ans 7th one
Dear Student
Corrosion is the process in which metals, are deteriorated by action of air, moisture, chemicals etc. Corrosion causes damage to car bodies, bridges, iron railings, ships and all objects made of metals (especially Iron). Iron in the presence of air and water, forms Iron (III) oxide, which is known as rust. The corrosion of Iron is called Rusting.
The reaction taking place at anode is given by:
The electrons released at the anodic spot move through the metal and reduce oxygen at another spot in the presence H+ ion. This spot behaves as cathode.
The reaction taking place at cathode is given by:
The overall reaction is
The Fe2+ ions thus formed are further oxidised by atmospheric oxygen to Fe3+ ions, and finally, it comes out as rust.
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