Rusting sim
Four identical iron nails, left for a week at room temperature.
Rusting · covers the GCSE, IGCSE, O-Level topic
What the sim shows
Four identical iron nails, left for a week at room temperature. Rusting is the slow oxidation of iron, and it needs oxygen and water together: 4Fe + 3O₂ + 2xH₂O → 2Fe₂O₃·xH₂O. Boiling the water drives out the dissolved oxygen and the oil stops more dissolving (B); the drying agent takes the water out of the air (C). Remove either one and rusting stops completely. Salt does not change the products; it makes the water conduct better, so rusting is faster (D). How quickly the rust spreads is this figure's estimate of a school result.
- Rust: hydrated iron(III) oxide
- Oil layer (B), drying agent (C)
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