The table shows data from life cycle assessments of two types of water pipe, each 10 m long.
| Copper pipe | PVC plastic pipe | |
|---|---|---|
| Energy used over the life cycle in MJ | 450 | 150 |
| Carbon dioxide emitted over the life cycle in kg | 30 | 9 |
| Expected lifetime in years | 50 | 25 |
| Percentage recycled at end of life | 90 | 10 |
A builder needs a water pipe that will last 50 years.
Which conclusion is justified by the data?
Over 50 years, PVC pipes use less energy and emit less carbon dioxide than copper
Over 50 years, copper uses less energy, because each copper pipe lasts twice as long
Over 50 years, PVC pipes use less energy but emit more carbon dioxide than copper
The PVC pipe has the lower environmental impact in every category in the table
45 exam-style questions on Edexcel GCSE Chemistry 5.1 Obtaining and using metals, covering 5.1.1 The reactivity series of metals, 5.1.2 Displacement reactions as redox reactions, 5.1.3 Extracting metals from ores by reduction, 5.1.4 Biological methods of metal extraction, 5.1.5 Resistance to oxidation and recycling metals, and 5.1.6 Life cycle assessment. Each one has a worked solution and a mark scheme showing where the marks go.