using resources - the harder process and NPK fertilizers Flashcards
(24 cards)
one use of ammonia
making nitrogen based fertilizers for farming
what produces ammonia
the harder process
what is the equation for the harder process
N2 + 3H2 = 2NH3
where do the reactants come from
nitrogen comes from the air, hydrogen can come from reacting methane with steam
what catalyst is used
iron
what temperature is used
450 degrees Celsius
what pressure is used
200 atmospheric pressure
what do these conditions cause
some of the nitrogen and hydrogen to react and form ammonia
the unused nitrogen and hydrogen…
are recycled
how can we increase the yield
we now cool the ammonia and turn it into a liquid
we can adjust the temperature and the pressure to shift….
the position of equilibrium towards the right hand side to produce more ammonia
harber process
forwards reaction….
backwards reaction….
forwards reaction = exothermic
backwards reaction = endothermic
what do we have a trade off between
the equilibrium and rate of reaction
what is 450 degrees celsius
a compromise temperature
high pressure will push the equilibrium to the …
right
why are fertilizers important
they are critical for modern farming as they replace elements which have been taken up by the plants
what do NPK fertilizers contain
compounds of nitrogen, phosphorus and potassium
NPK fertilizers are formulations of different…
salts
what do these salts contain
the required elements in the percentages required by the plant
main compound of nitrogen
ammonium nitrate - made by ammonia from the harbor process and nitric acid
potassium comes form…
potassium chloride or potassium sulphate - mined from the ground used directly
where doe sohospahte come form
the ground
