Past Papers Flashcards
Why does aluminium react with iron oxide?
Aluminium is more reactive
Why is copper now extracted from low grade ores?
High demand for copper
Now economical to extract from low-grade ores
Few high-grade ores left
Why would it be difficult to dispose of waste rock (from copper extraction)?
A lot of rock - takes up a lot of space
What are the advantages and disadvantages of recycling materials from a ballpoint pen?
Advantages
Less CO2 emissons
Not contributing to landfills
Disadvantages
Expensive to separate materials
Not all materials can be recycled
What is “locked up” CO2?
CO2 from the Earth’s early atmosphere which is in fossil fuels
What is the difference between ethanol and petrol?
Ethanol is one type of molecule; petrol is a mixture
Describe the process of fermentation
Yeast is added to sugar dissolved in water
Produces CO2 and ethanol
Advantages of ethanol as a fuel
Suga is renewable
Reduces CO2 emissons
Disadvantages of ethanol as a fuel
Releases less energy per litre than petrol
Crops should be for food rather than fuel
Less readily available than other fuels
How did the surface of the Earth change?
Earth cooled to form a crust layer and a supercontinent
How does fractional distillation separate crude oil?
It is heated and vapourised
Column hotter at the bottom
Vapours condense at different temperatures
