Question

What is the necessary conditions for rusting

Answer 1

Rust is the substance formed when iron compounds corrode in the presence of oxygen and water. It is a mixture of iron oxides and hydroxides. Rusting is a common term for corrosion, and usually corrosion of steel. 

Iron is found naturally in the ore haematite as iron oxide, and metallic iron tends to return to a similar state when exposed to air, (hydrogen, oxygen, nitrogen, etc.) and water. This corrosion is due to the oxidation reaction when iron metal returns to an energetically favourable state. Energy is given off when rust forms. The process of rusting can be summarized as three basic stages: The formation of iron(II) ions from the metal; the formation of hydroxide ions; and their reaction together, with the addition of oxygen, to create rust.

Or

Rusting of iron (Fe) is caused by oxidation of Fe to form Fe2O3.

The two essential conditions are: 

a) Presence of Oxygen

b) Presence of Water whose pH is in acidic range.

 

Rusting can be prevented by either Galvanizing iron or Coating it with Paint lacquer or varnish

Answer 2

Hey here's your answer
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Necessary conditions for rustling are presence of moisture and the contact of water and oxygen is essential for the rusting of iron
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