C2E - How Can We Make Fertiliser Flashcards
What is the equation for the Haber Process ?
Nitrogen + Hydrogen = Ammonia
what kind of reaction is the Haber Process ?
Reversible
Where is the nitrogen obtained from ?
The air
Where is the hydrogen obtained from ?
The cracking of oil fractions or natural gas
The reaction us reversible so what does that mean ?
Not all of the hydrogen and nitrogen will convert to ammonia
What happens to the nitrogen and hydrogen which don’t react ?
They are recycled and passed through again
What are the industrial conditions needed for the Haber process ?
High Pressure (200 atmospheres)
Temperature (450c)
Catalyst (Iron)
Why must there be a compromise with the Haber process ?
Because it’s reversible
What condition favours the forward reaction ?
High pressures
What will high pressures do ?
Increase the percentage yield of ammonia
What do high temperatures favour ?
The reverse reaction
What will decrease the percentage yield of ammonia ?
High temperatures
Why do manufactures not use low temperatures then ?
It will mean slow reaction rates
What is 450c and why ?
The optimum temperature because it gives a fast reaction rate and a reasonable percentage yield
What does the iron catalyst do ?
Makes the reaction go faster which will get it to equilibrium proportions more quickly
Does the catalyst actually effect the position of equilibrium ?
No
What would happen if a catalyst wasn’t present ?
You’d have to raise the temperature more which will decrease the percentage yield
Production cost depends on 5 factors. What are they ?
Price of energy Cost of raw materials Labour costs Plant costs Rate of production
The higher the temperature the higher the ?
Cost
How would a company reduce the cost of raw materials ?
Recycling any un reacted materials
What is one way of reducing labour costs ?
Using automation instead of people
Explain the plant costs ?
Equipment that needs to withstand higher pressure will cost more than equipment that needs to withstand atmospheric pressure
How can cost be kept down on rate of production?
Using a catalyst
Optimum conditions are what ?
Those that give the lowest production cost
