A plant is grown on soil containing nickel compounds, to extract the nickel by phytoextraction.
The plants harvested from one field have a dry mass of 10 tonnes.
When the plants are burned, the mass of ash is 5% of the dry mass of the plants. The ash contains 8% nickel by mass.
1 tonne = 1000 kg
What is the maximum mass of nickel that can be obtained from the ash?
4 kg
40 kg
400 kg
1300 kg
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.