The Rusting of Iron and its Prevention Flashcards
1
Q
What causes rust?
A
Water and Oxygen
2
Q
______ increases rate of corrosion/rust due to presence of salt
A
Seawater
3
Q
______ does not rust.
A
Aluminium
4
Q
What metals rust?
A
Iron (steel)
5
Q
What is an oxidising agent?
A
A substance that causes another substance to be oxidised
6
Q
Methods of rust prevention:
A
- Painting
- Oiling and greasing
- Plastic coatings
- Electroplating
- Galvanising
- Sacrificial protection
- Electrolytic protection
7
Q
Explain electroplating.
A
Coat with unreactive metal
8
Q
Explain galvanising.
A
- Iron or steel object is coated in a thin layer of a more reactive metal, zinc
- Protections still work if zinc layer is badly scratched
9
Q
Explain sacrificial protection.
A
- BLOCKS of a reactive metal are attached to the iron surface
- These metals are more reactive than iron and will be corroded in preference to it
10
Q
Explain electrolytic protection.
A
Setting up an electrolytic cell using the iron or steel object as the negative electrode of the cell
