The Haber Process/ Redox Reactions

Question 1

What does the Haber process produce?

Answer 1

Ammonia

Question 2

How is ammonia separated from unreacted H2 and N2

Answer 2

Since ammonia is liquefied

Question 3

What is ammonia used for?

Answer 3

For the manufacture of fertilizers

Question 4

Explain the steps of the Haber process

Answer 4

H2= from natural gas N2= from air. These gases are pumped into the compressor through the pipe, the gases are compressed at 200 atmospheres.

H2 and N2 are pumped into the tank containing layers of iron catalyst beds at 450C degrees. Some of the hydrogen and nitrogen react to form ammonia.

H2,N2 and product ammonia then pass into the cooling tank where the ammonia is liquified and removed into the pressurized storage vessels.

The unreacted H2 and N2 are then recycled back and start the process again.

Question 5

Why does the iron speed up the process in the tank?

Answer 5

Because it is a catalyst

Question 6

Why is a higher temp than 450 not used for the Haber process?

Answer 6

At a higher temp, it favours the reverse reaction, since at high temperatures it is endothermic since more heat is taken in. Causing a higher yield of reactants to be made (H2 and N2 in this case)

Question 7

Why is a lower temp than 450 not used for the Haber process?

Answer 7

At lower temperatures, it favours the forward reaction since at lower temperatures more heat is released and so will cause a higher yield of products to be made. Which is good since more ammonia will be produced, however the rate of reaction will be very slow due to low temperatures since particles need kinetic energy to react.

Question 8

What are the things limiting to how high we make the pressure and heat?

Answer 8

Heat: generating heat is expensive
Pressure: high pressure is dangerous and unsafe, and expensive as well.

Question 9

Why is a higher pressure than 200 not used? What happens when a higher pressure is used?

Answer 9

Higher pressure favours forward reaction so the system can decrease the pressure, in order to make less molecules. Higher yield of products will be made. Which is good however at high pressures it is costly and unsafe.

Question 10

Why is a lower pressure than 200 atmospheres not used? what happens when it is used?

Answer 10

Lower pressures favour reverse reaction so that the system can produce more molecules. A higher yield of reactants being made. However at lower temperatures, which reduces frequency of collisions between particles so the rate of reaction will be slower.

Question 11

What is collision theory?

Answer 11

A chemical reaction can only occur when the reacting particles collide with eachother with sufficient energy.