Production & Use of Fertilisers Flashcards

All 9 cards in this deck

Which three elements do NPK fertilisers contain compounds of?

Nitrogen, phosphorus and potassium.

e.g. potassium nitrate supplies K and N.

True or false? Ammonium nitrate on its own supplies all three of the NPK elements.

False. Of N, P and K it contains only nitrogen; NPK fertilisers are formulations of several salts.

Which two types of substance used in fertiliser manufacture are made from ammonia?

Ammonium salts (e.g. ammonium sulfate) and nitric acid.

How are potassium chloride, potassium sulfate and phosphate rock obtained?

By mining (quarrying).

What property of phosphate rock means it cannot be used directly as a fertiliser?

It is insoluble in water, so plants cannot absorb it.

Give three ways industrial production of a fertiliser salt differs from its laboratory preparation.

Industrial production is on a much larger scale, is quicker, and is a continuous process (the laboratory method is small scale, slower and must be repeated in batches).

True or false? An NPK fertiliser is a formulation — a mixture of salts blended to give appropriate percentages of the elements.

True. NPK fertilisers are formulations of various salts, not a single compound.

Which salt useful as a fertiliser is named as the product when phosphate rock (calcium phosphate) is treated with nitric acid?

Calcium nitrate.
It is formed along with phosphoric acid.

What fertiliser products are named when phosphate rock (calcium phosphate) is treated with sulfuric acid, and when it is treated with phosphoric acid?

Sulfuric acid: single superphosphate (calcium phosphate and calcium sulfate).
Phosphoric acid: triple superphosphate (calcium dihydrogenphosphate).