test Flashcards
What are fertilisers?
Fertilisers provide mineral ions needed for healthy growth in plants.
How do plants absorb mineral ions?
Plants absorb mineral ions from the water in the soil through their root hair cells.
Why do farmers add fertilisers to the soil?
Farmers add fertilisers to the soil to replenish the decreasing concentration of mineral ions.
In what form are fertilisers usually sold?
Fertilisers are usually sold as solid powders or granules.
What three elements do NPK fertilisers supply?
Nitrogen, phosphorus, and potassium.
What must fertiliser compounds be in order to be absorbed by plants?
Fertiliser compounds must be soluble in water.
What are sources of soluble nitrogen in fertilisers?
- Ammonium ions, NH4+
- Nitrate ions, NO3-
What is the source of soluble phosphorus in fertilisers?
Phosphate ions, PO43-.
What do all common potassium compounds do in water?
All common potassium compounds dissolve in water to produce potassium ions, K+.
What essential elements does ammonium nitrate provide?
Nitrogen.
What essential elements does ammonium phosphate provide?
Nitrogen and phosphorus.
What essential elements does potassium nitrate provide?
Potassium and nitrogen.
What essential element does urea provide?
Nitrogen.
What is ammonia’s role in making fertilisers?
Ammonia produces the ammonium ion (NH4+) which is present in many fertilisers.
What can ammonia be oxidised to make?
Nitric acid (HNO3).
What is the product of neutralising ammonia with nitric acid?
Ammonium nitrate (NH4NO3).
What is the equation for the reaction between ammonia and nitric acid?
NH3 + HNO3 → NH4NO3.
What is mined from the crust for use in fertilisers?
Minerals.
Can phosphate rock be used directly as a fertiliser?
No, phosphate rock cannot be used as a fertiliser because it is insoluble.
What useful soluble compounds are produced when phosphate rock reacts with nitric acid?
Calcium nitrate and phosphoric acid.
What is produced when phosphate rock reacts with sulfuric acid?
Single superphosphate.
What is produced when phosphate rock reacts with phosphoric acid?
Triple superphosphate.
