ABSTRACT
Rusting is simply a redox reaction between iron and oxygen in the presence of moisture. The moisture can be as little as what is in the air. Since iron and steel products rust quickly, they are often galvanized or coated in some other way to inhibit rusting and eventual deterioration. A galvanized steel product has a zinc coating on the surface to help prevent this reaction from occurring. Unlike other coatings, the zinc does not just put an extra layer between the iron and oxygen like paint does; instead, it sacrificially reacts with the oxygen to form zinc oxide. Since moisture is normally present, it is converted to zinc hydroxide, which will then react with carbon dioxide in the atmosphere to form a layer of zinc carbonate. The zinc carbonate actually forms a protective impermeable layer over the zinc below it. The area of chemistry that studies why zinc is an excellent protective coating for iron is called electrochemistry.
