This question is about fertilizers.
Compounds containing nitrogen (N), phosphorus (P), and potassium (K) are commonly used as fertilizers to increase crop yields.
The table below shows information about three compounds, Compound A, Compound B, and Compound C, that can be used as fertilizers.
| Compound | Name | Formula | Nutrient composition by mass | Cost (£/kg) |
|---|---|---|---|---|
| Compound A | ammonium nitrate | NH4NO3\text{NH}_4\text{NO}_3NH4NO3 | N:35%\text{N}: 35\%N:35% | 0.32 |
| Compound B | potassium chloride | KCl\text{KCl}KCl | K:52%\text{K}: 52\%K:52% | 0.22 |
| Compound C | diammonium hydrogen phosphate | (NH4)2HPO4(\text{NH}_4)_2\text{HPO}_4(NH4)2HPO4 | N:21%\text{N}: 21\%N:21%, P:23%\text{P}: 23\%P:23% | 0.45 |
An agricultural scientist tested a sample of soil and found that:
Evaluate the use of compounds Compound A, Compound B, and Compound C to improve the agricultural productivity of this soil.
8 exam-style questions on AQA GCSE Chemistry 10.4 The Haber process and the use of NPK fertilisers, covering 10.4.1 The Haber process and 10.4.2 Production and uses of NPK fertilisers. Each one has a worked solution and a mark scheme showing where the marks go.