The table shows the energy needed at different stages of producing 1 tonne of aluminium.
| Stage | Energy (GJ per tonne) |
|---|---|
| Extracting aluminium from its ore | 200 |
| Collecting and sorting used aluminium cans | 6 |
| Melting used cans to make new aluminium | 10 |
What percentage of energy is saved by making aluminium from used cans instead of from its ore?
8%
92%
95%
97%
136 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.