A garden centre sells four lawn fertilisers, each in a 20 kg sack. The manager plans to stop stocking the product that supplies nitrogen at the highest cost.
| Product | Percentage of nitrogen by mass (%) | Cost per sack (£) |
|---|---|---|
| Product W | 12 | 9.00 |
| Product X | 30 | 21.00 |
| Product Y | 18 | 15.00 |
| Product Z | 25 | 20.00 |
Which product has the highest cost for each kilogram of nitrogen it supplies?
Product Y
Product Z
Product W
Product X
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.