Duralumin is an alloy of aluminium containing about 4% copper by mass. It is used to make aircraft parts.
Statement 1: Duralumin is used for aircraft because it has a low density and is stronger than pure aluminium.
Statement 2: Duralumin is a compound, because the copper and aluminium atoms are chemically bonded together.
Statement 3: The copper atoms are a different size from the aluminium atoms, so the layers of atoms cannot slide over each other as easily.
Statement 4: Duralumin has a much higher density than pure aluminium, because copper is much denser than aluminium.
Which statements are correct?
1 and 3 only
1, 3 and 4 only
2 and 3 only
1, 2 and 3 only
61 exam-style questions on OCR GCSE Chemistry 6.1 Improving processes and products, covering 6.1.1 Extracting metals industrially and by electrolysis, 6.1.2 Life cycle assessment and recycling, 6.1.3 Biological methods of metal extraction, 6.1.4 The Haber process and the production of fertilisers, 6.1.5 Alloys and their uses, 6.1.6 Corrosion and its prevention, 6.1.7 Comparing and selecting materials, and 6.1.8 Industrial conditions, rate and position of equilibrium. Each one has a worked solution and a mark scheme showing where the marks go.