NPK FERTILISERS

Question 1

why are fertilisers important for modern farming

Answer 1

they replace the elements which have been taken up the plants

Question 2

what compounds do NPK fertilisers contain

Answer 2

Nitrogen
Phosphorus
Potassium

Question 3

what is the main compound of nitrogen in NPK fertilisers

Answer 3

ammonium nitrate (NH4NO3)

Question 4

how do you produce ammonium nitrate

Answer 4

we use ammonia produced by the Haber Process

We can then use this ammonia to produce nitric acid

then we react the nitric acid with more ammonia to make AMMONIUM NITRATE

Question 5

name 2 sources of potassium for NPK fertilisers

Answer 5

• potassium chloride

- potassium sulfate

Question 6

how to extract potassium chloride/sulfate

Answer 6

mine the compounds from the ground and can be used directly without any further processing

Question 7

when you treat phosphate rock with nitric acid what 2 products are formed

after you form these products what do you do to get the phosphorus

Answer 7

phosphoric acid and calcium nitrate

you neutralise the phosphoric acid with ammonia this produces ammonium phosphate

Question 8

1. if you react phosphate rock with sulfuric acid what 2 products are formed
2. what is this mixture called

Answer 8

1. calcium phosphate and calcium sulfate

2. single superphosphate

Question 9

1. if you treat phosphate rock with phosphoric acid what is the mixture called

Answer 9

1. triple superphosphate

Question 10

when you react ammonia with nitric acid what type of reaction is it

Answer 10

neutralisation reaction

Question 11

compare producing ammonium nitrate in industry and in the school lab

Answer 11

school lab - dilute solutions of ammonia and nitric acid so that it is safe to work with

produce crystals with a water bath and a bunsen this requires a lot of heat energy

can only produce a small amount of ammonium nitrate BATCH PROCESS

industry- ammonia is used as a gas and nitric acid is concentrated. This is dangerous as the reaction is exothermic so the heat produced has to be removed safely and then this heat is used during further stages

some of the energy needed for the evaporation is provided by the exothermic reaction earlier

the chemical is produced by a CONTINUOUS PROCESS so thousands of kilograms can be produced easily