Unit 3 ii) Fertilisers Flashcards
What are nutrients?
Nutrients : are soluble compounds which are absorbed through the roots.
Nutrients will contain at least 1 of the three key elements that are required by plants. What are they?
Nitrogen N
Phosophorus P
Potassium K
What do plants need for photosynthesis?
Carbon Dioxide + Water
However they also need nutrients to grow efficently
Name 2 natural fertilisers?
Compost
Manure
Name the 2 types of fertilisers?
Natural
Synthetic
How are synthetic fertilisers produced?
neutralisation reactions:
acid + base –> salt + water
the salt produced will be used as fertiliser
What must a fertiliser contain and be?
must contain one of 3 elements and be soluble
The percentage of key elements(N,P,K) present can be calculated using what formula?
percentage mass =
total mass of element / gfm of compound
x100%
Environment problems of fertilisers?
- rain can wash fertilisers from fields into rivers
- this causes algae to grow rapidly removing oxygen from the water
- without oxygen fish will die
What is the name for nitrogen hydride?
Ammonia
where do the reactants come from for the Haber process?
n2 from air
h2 from natural gas
what are the reaction conditions needed for the haber process?
- catalyst (iron metal)
- moderate temperature
- moderate pressure
What is the Ostwald Process?
Ammonia
nitrogen dioxide
nitric acid
nitrate salts (important synthetic fertilisers)
What catalyst is used in Ostwald Process?
Platinum: continues to glow when heat is removed because oxidation of ammonia is exothermic
