TOPIC 10 - The Global Saviour!1!!1 (Fertilisers) Flashcards
The chemist has the important role in making sure
plants have the correct nutrients to ensure sufficient food production.
Key elements which provide nutrients required for plant growth:
nitrogen, phosphorus and potassium.
Fertilisers can be produced
naturally or in a lab using neutralisation reactions
The Haber process can be
reversed
At high temperatures the rates of both the forwards and backwards reactions for the Haber process
are increased; however, the backwards reaction is more dominant.
ammonia is the staring material for the commercial production of
nitric acid which is used to produce ammonium nitrate.
The Haber process is used to produce
ammonia
Using fertilisers may have an impact
environmentally
analytical techniques: (5)
Colourimetry, flame tests, pH measurements, titrations, precipitation reactions
water becomes polluted by mud containing
metals that are harmful to us
the soil in developing countries lacks
the essential nutrients that plants require to grow healthily
Nitrogen is essential for (1)
growth
Potassium is essential for (2)
respiration and photosynthesis
Phosphorus is essential for (2)
respiration and growth
effect of being deficient in Nitrogen (2)
poor growth and discoloured leaves
effect of being deficient in Potassium (1)
poor fruit/flower growth
effect of being deficient in Phosphorus (2)
poor root growth and discoloured leaves
what is a fertiliser
a natural or manmade compound which contains one or more of the essential elements potassium, phosphorus or nitrogen
KPO4
potassium phosphate
NH4Cl
ammonium chloride
NH4NO3
ammonium nitrate
(NH4)2SO4
ammonium sulphate
KNO3
potassium nitrate
CO(NH2)2
urea
(NH4)3PO4
ammonium phosphate
a complete fertiliser contains
potassium, nitrogen and phosphorus
formula to find %nitrogen
%nitrogen = (mass of nitrogen/total compound gFm) x 100
the Haber process was one of the first ways to make a
synthetic fertiliser
ammonia is also called
nitrogen hydride
the Haber process is a way of getting a very unreactive nitrogen gas to react with hydrogen gas using
a moderate temperature and an iron catalyst
N2(g) + 3H2(g) <=> 2NH3(g)
Haber process
NH3(g) + H20(l) => NH4OH(aq)
ammonia dissolving in water
nearly all fertilisers are
salts (alkalis) which makes them easily dissolved in water
one of the worlds most common fertilisers is ammonium nitrate which is made by
ammonium hydroxide with nitric acid
the Ostwald process produces
nitric acid
the Ostwald process uses
ammonia, oxygen and water to produce nitric acid
NH3 + O2 + H2O => HNO3
the Ostwald process
catalyst used in the Haber process
iron
catalyst used in the Ostwald process
platinum
a precipitation reaction is when
a solid called a precipitate forms
if silver is added to sodium chloride solution then insoluble
silver chloride`
if lead is added to potassium iodide solution then insoluble
lead iodide
if barium is added to sodium sulphate solution then insoluble
barium sulphate
some transition metal ions can form compounds called
complexes which have intense colours
