Chemically rust is

Chemically, rust is hydrated ferric oxide, a compound formed by the reaction of iron (Fe), water (H₂O), and oxygen (O₂). The process, known as corrosion, can be represented by the chemical formula:

4Fe + 6H₂O + 3O₂ → 4Fe(OH)₃

The compound Fe(OH)₃ further dehydrates to form hydrated ferric oxide, which is rust. The general formula for rust is:

Fe₂O₃ · xH₂O

Here, x represents the variable amount of water molecules in the compound.

Key Points

• Chemically, rust is formed due to oxidation and hydration of iron.
• Rusting weakens iron by turning its surface into a brittle, flaky material.
• The reddish-brown appearance of rust is a characteristic of hydrated ferric oxide.

Real-World Implication

Rust can cause significant structural damage to iron-based materials over time, which is why preventive measures like painting, galvanizing, or using rust-resistant alloys are essential.