A builder is choosing between copper pipes and plastic (PVC) pipes for a water supply.
The table shows some data from a life cycle assessment for 10 m m\,m of each type of pipe.
| Stage | Copper pipe | PVC pipe |
|---|---|---|
| energy to obtain raw materials / MJ | 150 | 60 |
| energy to manufacture pipe / MJ | 90 | 70 |
| expected lifetime / years | 50 | 25 |
| disposal | can be recycled | usually sent to landfill |
Give the name of the stage of a life cycle assessment in which the pipe is recycled or sent to landfill.
Calculate the total energy needed to obtain the raw materials and manufacture 10 m m\,m of copper pipe.
Calculate the energy used per year of lifetime for each type of pipe.
Use your answers to (c) to state which pipe has the lower energy cost. Give a reason.
Give one limitation of a life cycle assessment.
Give one advantage of recycling copper pipes at the end of their life.
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.