SC15a Fertilisers and the Haber Process Flashcards
what can happen when plants don’t get the nutrients they need? 3
plants not growing properly
suffering from deficiency diseases:
stunted shoots and discoloured leaves.
what do fertilisers do?
replace the minerals in the soil and promote plant growth.
what 3 compounds can be used in fertilisers?
Nitrogen, phosphorus and Potassium
how is ammonium nitrate made?
ammonia(from haber process) + nitric acid(made using ammonia) → ammonium nitrate
how is nitric acid made?
ammonia + oxygen → nitric acid + water
write the formula for ammonium nitrate
NH3(aq) + HNO3(aq) → NH4NO3(aq)
write the formula for nitric acid
NH3(g) + 2O2(g) → HNO3(aq) + H2O(l)
core practical - making ammonia
- Measure 10cm3 of dilute sulfuric acid into the beaker.
- Add approximately 1cm3 of ammonia solution using the dropping pipette.
- Briefly stir the reaction mixture with the glass rod.
- Put a piece of universal indicator paper onto the white tile. Dab a small spot of the reaction mixture onto the paper using the end of the glass rod, then use the pH colour chart to estimate its pH.
- Repeat steps 2–4 until the reaction mixture reaches pH 7, then add about 2cm3 of ammonia solution.
- crystallisation steps
what is the laboratory preparation of ammonium sulfate
~small scale
~starting materials - ammonia solution and dilute sulfuric acid
~stages - titration and crystallisation
~batch process
what is the industrial preparation of ammonium sulfate
~large scale
~Raw materials for making ammonia and sulfuric acid
~several stages
~continuous process
Suggest reasons that explain why farmers may apply NPK fertilisers to their fields.
(2 marks)
NPK fertiliser provides nitrogen, phosphorus an potassium. (1)
These elements are needed to promote plant growth and increase crop yields. (1)
