Recall the simplified equation for corrosion:
Metal + Oxygen -> Metal Oxide
E.g. Iron + Oxygen -> Iron (III) Oxide
Design a fair test to determine the factors that promote corrosion
Analyse some results of some fair tests on factors that promote corrosion
Corrosion requires an active metal and oxygen gas or water. It is accelerated by the presence of
- salt
- acid
- heat
Outline some strategies used to prevent corrosion including submerged objects
Most ways of preventing corrosion relying on insulating the metal from oxygen.
| Method | Description | Photo / Diagram |
|---|---|---|
| Paint | Paint creates a physical layer that stops moisture and air from reacting with the metal. |  |
| Grease | Grease also creates a physical barrier that stops moisture and air from attacking the metal. | |
| Plastic | Acting as a physical barrier that seals out moisture, oxygen, and corrosive chemicals | |
| Galvanising | Iron is coated in zinc, which stops oxygen/water from attacking the iron. |  |
| Chrome Plating | Coats the object in atoms of a less reactive metal, slowing process of corrosion |  |
| Sacrificial Protection | The iron or steel object is coated in a metal from higher up the chain of reactivity, created both a chemical and physical barrier. |  |
| Tin Plating | A uniform layer of tin covers the metal, preventing oxygen from contacting it. |  |
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