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Hom 10T Name: Furkan Yiğit Alataş 10/A 832
14 Making use of metals
Core curriculum
1 Which statement is not correct about metal alloys? Tick its box.
A They are attracted to a magnet.
B They are mixtures.
C They conduct electricity.
D They have different properties from pure metals.
2 Which of these will you choose, if you want a strong light metal that resists corrosion? Tick its box.
A aluminium B lead C iron D sodium
3 Complete this paragraph about the extraction of iron.
Iron is extracted from an ore called hematite , in a
blast furnace.
The other raw materials are coke and limestone Coke is almost pure
carbon , and burns in oxygen to form carbondioxide This reacts with
carbonmonoxide reducing
more coke to form , which acts as the agent.
The two waste gases from the extraction are CO2 and nitrogen
4 For many uses, pure metals are turned into alloys.
This diagram shows the structure of an alloy.
a What is an alloy? The mixture of any substance with
metals
b Give two examples of metal properties that can be improved by making alloys.
Hard, Sonorous
c i There are many different steels. Name the main metal in them: Iron
ii Other metals are added to this metal, to make the alloy stainless steel. Name two of them:
chlorium and nickel
d Brass is an alloy of the metals copper and
zinc Unlike those two
metals, it has this new property: harder
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WORKSHEET
Extended curriculum
5 a Complete these sentences about the extraction of aluminium by electrolysis.
The main ore of aluminium is called
bauxite ore . The compound obtained from it, for
electrolysis, is called aluminium oxide and its formula is Al2O3
b This diagram shows a cross-section of the electrolysis cell used in extracting aluminium:
oxygen bubbling off
steel cell ore dissolved in molten
cryolite at about 950 8c
molten aluminium
molten aluminium out
c i Label the anode and cathode, on the diagram.
ii What are the electrodes made of? carbon
d One electrode must be replaced at intervals, because it is destroyed in a chemical reaction.
i Which electrode is it? Anode
ii What reaction takes place?
C + O2 = CO2
e Why is cryolite needed?
For the aluminium to be dissolved.
f During the extraction, aluminium ions are reduced. Give the half-equation for this reaction:
Al + 3E = Al (I)
6 a Aluminium has many uses. Give reasons why it is used:
i to make food containers healthy
ii in electricity cables good conductor
b In air, the surface of aluminium is quickly coated with a thin layer of aluminium oxide.
Comment about the effect of this on the apparent reactivity, and uses, of aluminium.
It makes aluminium more like a metal to be used in structures.
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