Rusting is the corrosion of iron (or steel) in the presence of oxygen and moisture, forming a reddish-brown flaky layer called rust (hydrated iron(III) oxide, Fe₂O₃·xH₂O).
KEY POINTS:
📌 CHEMICAL REACTION:
📒 Iron reacts with oxygen and water: 4Fe + 3O₂ + 6H₂O → 4Fe(OH)₃
📒 Further oxidation forms rust: 2Fe(OH)₃ → Fe₂O₃·xH₂O (rust) + 3H₂O
📌 REQUIREMENTS FOR RUSTING:
📒 Presence of oxygen (O₂) and water (H₂O).
📒 Electrolytes (e.g., salt) accelerate rusting.
📌 EFFECTS:
📒 Weakens the metal structure.
📒 Causes economic losses due to material degradation.
📌 PREVENTION METHODS:
📒 Barrier Protection: Painting, oiling, or coating with plastic.
📒 Galvanization: Coating iron with zinc.
📒 Sacrificial Protection: Using more reactive metals (e.g., magnesium or zinc) as anodes.
📒 Alloying: Using stainless steel (iron + chromium/nickel).
Rusting is an electrochemical process and a major concern in industries, requiring preventive measures for durability.
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