C10: THE HABER PROCESS + FERTILISERS Flashcards
What is ammonia used to make?
fertilisers
What is ammonia made from? (+where do the elements come from?)
-nitrogen (from atmosphere)
-hydrogen (from natural gas)
What is the name of the process whereby ammonia is made?
the Haber process
What is the equation for the reaction to produce ammonia?
N2 + 3H2 ⇌ 2NH3
Descibe the Haber process?
-nitrogen extracted from air and hydrogen from natural gas are pumped through pipes
-the pressure of the mixture of gases is increased to 200 atm
-the pressurised gases are heated to 450°C and passed through a tank containing an iron catalyst
-the reaction mixture is cooled so that ammonia liquefies and can be removed (unreacted nitrogen and hydrogen are recycled)
What are the conditions required for the Haber process?
-iron catalyst
-temp of ~450°C
-high pressure of 200 atm
Why is an iron catalyst used?
-increases rate of reaction by lowering activation energy
-no effect on yield
Why is a temp of ~450°C used?
-increases rate of reaction (more kinetic energy so more frequent and more successful collisions)
-high temp decreases yield so a compromise temp of ~450°C is used (high enough for fast rate, not too high that yield is low)
Why is a pressure of 200 atm used?
-increases rate of reaction (more frequent collisions)
-increases yield
What are fertilisers?
formulations of various salts that provide mineral ions needed for healthy growth in plants
What are NPK fertilisers?
fertilisers containing nitrogen (N) , phosphorus (P) and potassium (K)
Where does the nitrogen used in NPK fertilisers come from?
from ammonia in Haber process
Where does the phosphorous used in NPK fertilisers come from?
from phosphate rock
Where does the potassium used in NPK fertilisers come from?
from mining KCl(Potassium chloride) and K2SO4(Potassium sulfate)
What salts are manufactured from ammonia and how?
-ammonium phosphate ((NH4)2PO4) (made by reacting ammonia with phosphoric acid)
-ammonium sulfate ((NH4)2SO4) (made by reacting ammonia with sulfuric acid)
-ammonium nitrate (NH4NO3) (made by converting ammonia into nitruc acid then reacting ammonia with the nitric acid)