Reversible reactions, industrial processes and important chemicals

What is the equation for the haber process?

Nitrogen + Hydrogen ←> Ammonia

N2 + 3H2 ←> 2NH3

What conditions are needed for a manufacture of ammonia?

• 350 to 450 degrees

• 150 to 200 atmospheres

• Catalyst

Why is a high temperature and a low pressure used in harbour process?

A low Temperature is not used because the process would be too slow and a high-pressure is not used because it’s too expensive

What are the stages of making ammonium by the harbour process?

1. Hydrogen and nitrogen are pumped into the compressor through pipes

2. The gases are pressurised to about 200 atm inside the compressor

3. The gases are pumped into a Tank containing bed of iron catalyst at about 450°

4. The unreacted nitrogen and hydrogen together with the ammonia pass into a cooling tank Which liquefies the ammonia which can be removed into pressurised storage vessels

5. The unreacted hydrogen and nitrogen are Recycled by being fed through the pipes to pass through the hot iron catalyst beds again

What are the raw materials needed to make sulphuric acid in the contact process?

• sulfur

• Air

• Water

What is the first stage of the contact process?

Sulfur is burned to make sulfur dioxide

Sulfur + Oxygen —> Sulfur dioxide

S + O2 —> SO2

What is the second stage of the contact process?

Sofa dioxide reacts with more oxygen to make sulphur trioxide

Sulfur dioxide + Oxygen ←> Sulfur trioxide

2SO2 + O2 ←> 2SO3

What are the conditions needed to make stage two in the contact process reversible?

• A catalyst of vanadium oxide-V2O5

• A temperature of around 450°

• Atmospheric pressure

What is stage three of the contact process?

Sulfur trioxide reacts with water to make Sulfuric acid

H2O + SO3 —> H2SO4

Why can’t sulphur trioxide be absorbed directly in 100% water?

The reaction is too violent and produces a mist of the acid

What are the uses of sulphuric acid?

• As a dehydrating agent

• Making fertiliser

• Paints and dyes

What are the equations for making fertiliser with sulphuric acid?

Ammonia + Sulfuric acid —> Ammonium sulfate

Ammonium hydroxide + Sulfuric acid —> Ammonium sulfate + Water

What are the advantages of fertilisers?

• Healthier plants

• Cheap

• Increases crop yields

What are the disadvantages of fertilisers?

• eutrophication

• Could enter water supply and cause blue baby syndrome

How do you test for ammonia?

Ammonia gas will change damp red litmus paper blue but you can also recognise it from its pungent smell