Using Materials (AQA GCSE Chemistry): Flashcards
📚Flashcards
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13 cards from this deck
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Practise the cards
13 cards from this deck
Corrosion
Corrosion
Materials break down by reacting with oxygen & water
Main chemicals causing corrosion
Main chemicals causing corrosion
Oxygen and water
Rusting
Rusting
Corrosion of iron or steel
Chemical formula of rust
Chemical formula of rust
(iron oxide), orange-brown colour
Conditions needed for iron to rust
Conditions needed for iron to rust
Both air AND water (not just one)
Why aluminium resists corrosion
Why aluminium resists corrosion
Natural protective coating keeps air & water away
Barrier method to prevent corrosion
Barrier method to prevent corrosion
Keep air and water away from metal surface
Examples of barrier corrosion prevention
Examples of barrier corrosion prevention
Grease, paint, electroplating
Sacrificial protection
Sacrificial protection
More reactive metal corrodes instead of protected metal
Example of sacrificial protection
Example of sacrificial protection
Magnesium blocks on steel ships
Galvanising
Galvanising
Covering iron with zinc
Why galvanising works when scratched
Why galvanising works when scratched
Zinc is more reactive than iron, so zinc corrodes first
Rule for choosing metal for sacrificial protection
Rule for choosing metal for sacrificial protection
Must be more reactive than metal being protected