Metals1. Alloys have many important uses.

(a) State the meaning of the term alloy.

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(b) This wedding ring is made from 18 carat gold. This is an alloy made from gold and silver.

The wedding ring has to last many years when worn every day.

Suggest and explain why the ring is made from an alloy rather than pure gold.

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(c) The metal frame of these glasses is made from a smart alloy. This alloy is made from titanium and nickel.

Give one advantage of making the frame from a smart alloy, instead of an ordinary metal.

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(Total 4 marks)

2. The table gives information about some metals.

Name of the metal Cost of one tonne of themetal in December 2003 (£)

Percentage of the metalin the crust of the earth (%)

Aluminium 883 8.2

Platinum 16720000 0.0000001

Iron 216 4.1

Gold 8236800 0.0000001

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(a) Use information in the table to suggest why gold and platinum are very expensive metals.

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(b) Aluminium and iron are made by reduction of their ores.

(i) Name the element that is removed from the ores when they are reduced.

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(ii) Use the reactivity series to suggest a metal that would reduce aluminium ore.

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(c) Aluminium is made by the reduction of molten aluminium ore, using a very large amount of electricity.

(i) How is iron ore reduced in a blast furnace to make iron?

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(ii) Suggest why aluminium is more expensive than iron.

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(Total 6 marks)

3. Copper is a widely used metal. The main ore of copper contains copper sulfide. Copper can be extracted from copper sulfide in a three stage process.

(a) In the first stage of extraction the copper sulfide is heated in air.

(i) Balance the symbol equation for the reaction.

Cu2S ........O2 .........CuO SO2(1)

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(ii) Explain why there would be an environmental problem if the gas from this reaction were allowed to escape into the atmosphere.

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(b) In the second stage copper oxide, CuO, is reduced using carbon.

Describe and explain what happens during this reaction.

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(c) During the third stage the copper can be purified as shown in the diagram.

(i) What is the name of the type of process used for this purification?

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(ii) Give one use of purified copper.

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(d) Copper-rich ores are running out.

New ways of extracting copper from low grade ores are being researched.

Recycling of copper may be better than extracting copper from its ores.

Explain why.

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(Total 10 marks)Wyvern Technology College 3

4. One step in the manufacture of lead is the reduction of lead oxide with carbon. Lead and carbon dioxide are the products of this reaction.

(a) Write a word equation for this reaction.

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(b) What is meant by “reduction”?

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(Total 2 marks)

5. Part of a reactivity series is:

(a) Carbon is used in blast furnaces to obtain iron and zinc from their oxides, but electrolysis has to be used to obtain aluminium from its oxide.

Draw an arrow on the reactivity series above to show where carbon fits into the series.(1)

(b) Predict the method of extraction used to obtain calcium from its ore and explain your answer.

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(c) The formula for zinc oxide is ZnO. Write a balanced equation for the extraction of zinc in the blast furnace.

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(d) Sodium is obtained by the electrolysis of a molten mixture containing sodium ions.

(i) What is the formula for a sodium ion?

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(ii) Write a balanced ionic equation for the formation of sodium from sodium ions.

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(e) Give the symbol for a metal which is more reactive than sodium.

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(Total 8 marks)

6. Use the Reactivity Series of Metals on the Data Sheet to help you to answer this question.

The table gives information about the extraction of some metals.

Metal Date of discovery Main source Main extraction method

Gold Known to ancient civilisations

In the Earth as the metal itself

Physically separating itfrom the rocks it ismixed with

Zinc 1500 Zinc carbonate Reduction by carbon

Sodium 1807 Sodium chloride Electrolysis

(a) Explain why gold is found mainly as the metal itself in the Earth.

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(b) One of the reactions involved in producing zinc is represented by this equation.

ZnO + C Zn + CO

Explain why carbon can be used to extract zinc.

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(c) Sodium is one of the most abundant metals on Earth.

Explain, as fully as you can, why sodium was not extracted until 1807.

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(Total 4 marks)

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7. Bridges are often made from steel.

(a) Explain, in terms of atoms, why pure iron would be too soft for making bridges.

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(b) The steel used for bridges is an alloy made from iron with a small amount of carbon.

Explain, in terms of atoms, how the addition of a small amount of carbon makes the steel suitable for bridges.

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(c) The strength of a metal can be tested by measuring the force needed to snap a wire made from the metal. An apparatus that could be used is shown in the diagram.

Great care must be taken, since, when the wire snaps, the end of the wire could hit somebody.

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C la m p

W ire

M a sse s

The apparatus is used to compare the strength of two different metals.

Suggest two variables that must be controlled in order to make the experiment a fair test.

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(d) Read the information below about the recycling of steel and then answer the questions.

Scrap steel reduces related water pollution, air pollution, and mining wastes by about 70%. It takes four times as much energy to make steel from virgin ore.

Recycling steel and tin cans saves 74% of the energy used to produce them from raw materials. At least 70–80% of the tin on a can is saved when you recycle it. This cuts down mining waste and preserves a valuable ore source.

Every time a ton of steel is recycled, 2 500 pounds of iron ore, 1 000 pounds of coal and 40 pounds of limestone are preserved.

The recycling process involves simply melting the scrap steel and then removing impurities.

(i) Explain why mining iron ore causes environmental problems.

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(ii) Explain why as much steel as possible should be recycled.

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(Total 11 marks)

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