A company delivers prepared food in stainless-steel catering trays. Each tray has a mass of 1.6 kg. A used tray can be washed and reused, or the steel can be melted and reformed into a new tray.
| Route and step | Energy used |
|---|---|
| Reuse - collection and return | 0.6 MJ per tray |
| Reuse - washing | 0.8 MJ per tray |
| Recycling - collection, sorting and transport | 1.1 MJ per tray |
| Recycling - melting and reforming | 8.0 MJ per kg |
Calculate how much less energy is used to prepare one tray for reuse than to recycle it.
Explain why these energy data are not enough to conclude that reuse has a lower overall environmental impact than recycling.
99 exam-style questions on AQA GCSE Chemistry 10.2 Life cycle assessment and recycling, covering 10.2.1 Life cycle assessment and 10.2.2 Ways of reducing the use of resources. Each one has a worked solution and a mark scheme showing where the marks go.