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Practise 27 exam-style questions on Alloys as useful materials (chemistry only) for AQA GCSE Chemistry. Write your answer as you would in the exam and get it marked in seconds against the mark scheme, point by point, with an AI tutor on hand if you get stuck.
Here are 4 of the questions in this topic, each with a model answer, an explanation of why it earns the marks and the mark scheme an examiner would use.
Bronze and brass are both alloys of copper.
Name the other metal in bronze and the other metal in brass.
Bronze is copper and tin. Brass is copper and zinc.
These two alloys are easily mixed up. Both are mainly copper: bronze, the alloy that gave the Bronze Age its name, contains tin, while brass contains zinc.
bronze: tin
brass: zinc
24 carat gold is 100% gold.
Calculate the percentage of gold in 22 carat gold, to 3 significant figures.
percentage of gold = (22 ÷ 24) × 100 = 91.666...% = 91.7% (3 significant figures)
Divide the carat number by 24 and multiply by 100. To round to 3 significant figures, look at the fourth figure (6), which rounds the third figure up.
22 ÷ 24 × 100
= 91.7 (%)
must be 3 significant figures for this mark; 91.666... alone scores 1 mark
Stainless steel is used to make cutlery.
Name the two metals, other than iron, that are added to make stainless steel. Give the property of stainless steel that makes it suitable for cutlery.
Chromium and nickel. Stainless steel is resistant to corrosion, so the cutlery does not rust when it is washed.
Steels containing chromium and nickel are stainless steels, which are hard and resistant to corrosion. That makes them ideal for cutlery, sinks and surgical instruments.
chromium
nickel
resistant to corrosion / does not rust
allow hard
The table shows information about four alloys.
Suggest which alloy is most suitable for the heating element in a toaster and which alloy is most suitable for making coins. Give a reason for each choice.
Nichrome should be used for the heating element because it has a very high melting point and does not react with air when it is hot. Cupronickel should be used for coins because it is hard, so the coins do not wear away, and it resists corrosion.
When choosing an unfamiliar alloy, match the properties in the data to what the use needs. A heating element gets very hot, so it needs a high melting point and must not react with air; coins are handled constantly, so they must be hard and resist corrosion.
heating element: nichrome
because it has a high melting point / does not react with air when hot
coins: cupronickel
because it is hard (so does not wear away) / resists corrosion / has a silver colour
Ready to try the rest? Every answer you write is marked against the mark scheme, so you can see exactly where the marks are.
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