Describe the limestone reaction cycle. (4)
- Calcium carbonate is thermally decomposed to make calcium oxide and carbon dioxide.
- Adding water to calcium oxide makes calcium hydroxide.
- Adding water & filter to calcium hydroxide will make limewater.
- Adding CO2 to limewater will form calcium carbonate.
How does quarrying limestone make a mess of the landscape? (4)
- Huge, ugly holes that change the landscape forever
- Quarrying processes make noise and dust
- Destroys habitats
- Noise and pollution caused by transport of limestone
What are the positives of quarrying and using limestone? (5)
- Provides houses/roads
- acidic lakes caused by acid rain and soil can be neutralised by limestone products
- used to neutralise sulfur dioxide in chimneys
- Quarrying provides jobs/brings money to the local economy/leads to improvements
- Restoration will happen after quarrying
How can the profitability of metal extraction change over time?
Price of metal: if it decreases it might not be worth it, if it increases it might be worth extracting more.
Technology: It becomes possible to extract more rock as it improves.
Explain how copper can be purified using electrolysis.
- Electrons are pulled off copper atoms at the positive electrode, causing them to go into the solution as Cu2+ ions.
- Cu2+ ions near the negative electrode gain electrons and turn back to copper atoms.
- The impurities are dropped at the positive electrode as sludge, while pure copper atoms bond to the negative electrode.
Explain how a displacement reaction works.
Putting a reactive metal into a solution of a dissolved metal compound will make the reactive metal will replace the less reactive metal in the compound.
-This is because the more reactive metal bonds more strongly to the non-metal bit of the compound and pushes out the less reactive metal.
Explain how bio-leaching uses bacteria to separate copper from copper sulfide to in order to extract copper from its ore.
The bacteria get energy from the bond between copper and sulfur, separating out the copper from the ore in the process. The solution produced (leachate) contains copper which can be extracted by filtering.
Explain how phytomining can be used to extract copper.
Plants that contain copper can’t use or get rid of it so the plants are grown and it builds up in the leaves. The plants are harvested, dried and burned in a furnace. The copper can be collected from the ash left in the furnace.
Explain why recycling metals is important.
- Fossil fuels need to be conserved
- Recycling saves the money used for energy
- Recycling conserves the finite amount of metal in earth
- Recycling metal decreases the amount of rubbish in landfills, which take up space and pollute the surroundings.
Which basic properties do metals have and what are some of the uses of these properties?
- Strong/bendy- bridges/car bodies.
- Good conductors of heat- Saucepan base.
- Good conductors of electricity- Electrical wires.
What are the exact properties of:
Copper
Aluminium
Titanium
- good conductor of electricity, hard, strong, bendy, doesn’t react with water.
- Corrosion resistant, low density.
- Low density, very strong, corrosion resistant.
What are the properties and uses of:
- Low carbon steel
- High carbon steel
- Stainless steel
- Easily shaped, car bodies
- Very hard/inflexible, bridges
- Corrosion resistant, cutlery
How does fractional distillation work?
Heated crude oil is piped in at the bottom of the fractionating column, and the vaporised oil rises up the column and the fractions are tapped off at the levels where they condense.
Name the first four alkanes. What is the formula for alkanes structure?
Methane, Ethane, Propane and Butane.
CnH2n+2
What are the basic trends about how the structure of alkanes affects the fractions properties?
- The shorter the molecules, the more runny or less viscous the hydrocarbon is.
- The shorter the molecules, the more volatile they are, and the lower the boiling point.
- The shorter the molecules, the more flammable the hydrocarbon is.
