The Haber Process

Question 1

What is ammonia made of?

Answer 1

Nitrogen and hydrogen (NH3).

Question 2

What are the industrial conditions for the Haber process?

Answer 2

1) pressure = 200 atmospheres
2) temperature = 450C
3) catalyst = iron

Question 3

What compromise has to be made? (pressure)

Answer 3

Higher pressures favour the forward reaction, so the pressure has to be as high as possible without being too expensive to build (200 atmospheres).

Question 4

What compromise has to be made? (temperature)

Answer 4

As the forward reaction is exothermic, increasing the temperature will move the equilibrium the wrong way so the yield of ammonia will be higher at lower temperatures. However, the rate of reaction will be too slow at lower temperatures, so they put the temperature up anyway (450C) to get the most yield at the lowest temperature.

Question 5

Why is there no waste?

Answer 5

The excess hydrogen and nitrogen are recycled so nothing is wasted.

Question 6

Why is an iron catalyst used?

Answer 6

It makes the reaction go quicker so gets into equilibrium positions more quickly without affecting the % yield of ammonia made. It also means the temperature would have to be raised even higher, lowering the yield even more.