3.3 Aluminium and Titanium Flashcards
Why can’t aluminium use carbon to displace it?
It is more reactive than carbon so need to use an element that is more reactive than aluminium
Why is it surprising that aluminium can resist corrosion?
It is quite high in the reactivity series
How do we extract aluminium?
Electrolysis
How does the electrolysis of aluminium work?
An electric current passes through molten aluminium oxide to break it down
Why is the electrolysis of aluminium so expensive?
Because it requires high temperatures therefore lots of electricity and also there are a lot of steps involved
Which is stronger, pure aluminium or aluminium alloys?
Aluminium alloys
Why is aluminium resistant to corrosion?
It’s surface is coated with a thin, tough layer of aluminium oxide
Name the steps to extract aluminium
- Mine aluminium ore
- Separate aluminium oxide from impurities
- Melt aluminium oxide
- Use electrolysis to extract the aluminium
Name the process for extracting titanium
- Extract sodium or magnesium using electrolysis to react with titanium
- Process the titanium ore by separating titanium oxide and converting it to a chloride
- Titanium chloride is distilled to purify it
- React titanium with sodium or magnesium to extract the titanium, as the sodium or magnesium will take the place of the titanium
Why can’t we is carbon to reduce titanium, especially since carbon is more reactive than titanium?
When carbon reacts with titanium it makes it very brittle, therefore useless
Why doesn’t titanium corrode?
It isn’t very reactive
Describe the density of titanium
Low density
Why is the extraction of titanium very expensive?
It has a lot of complex steps that each require lots of electricity
Name a use of titanium and why it is useful
•used to make artificial hip joints because of its low density, strength and resistance to corrosion
Name 3 properties of aluminium
- low density
- doesn’t corrode
- strong
