The Reaction is Reversible, So There’s a Compromise to be Made: Flashcards
What do higher pressures favour?
The forward reaction
Why is the pressure set as high as possible?
To give the best % yield, without making the plant too expensive to build - hence 200 atmospheres operating pressure
The forward reaction is Exothermic - what does this mean?
That increasing the temp will actually move the equilibrium the wrong way - away from ammonia and towards N2 and H2
The yield of ammonia would be ….. at lower temps
Greater
What is the trouble?
Lower temps mean a slower rate of reaction - increase temp anyway to get much faster rate of reaction
What is the 450°C a compromise between?
The maximum yield and speed of the reaction
The ammonia is formed as a gas, but as it cools in the condenser…
It liquifies and is removed
How is nothing wasted?
The unused hydrogen, H2, and nitrogen, N2, are recycled
What does the iron catalyst do?
Makes the reaction go faster, but doesn’t affect the % yield
See diagram page 75
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