AQA GCSE Chemistry

Revision Notes

10.4.1 The Haber Process

The Haber Process

  • Ammonia is manufactured using the Haber Process which occurs in five stages
  • The reactants are hydrogen and nitrogen which are extracted from methane and the air respectively
  • Stage 1: H2 and N2 gases are pumped into the compressor through pipes
  • Stage 2: The gases are compressed to about 200 atmospheres inside the compressor
  • Stage 3: The pressurised gases are pumped into a tank containing layers of catalytic iron beads at a temperature of 450°C. Some of the hydrogen and nitrogen react to form ammonia in the following reversible reaction:

N2 (g) + 3H2 (g) 2NH3 (g)

  • Stage 4: Unreacted H2 and N2 and product ammonia pass into a cooling tank. The ammonia is liquefied and removed to pressurised storage vessels
  • Stage 5: The unreacted H2 and N2 gases are recycled back into the system

, IGCSE & GCSE Chemistry revision notes

The production of ammonia by the Haber Process

Exam Tip

The air contains 78% nitrogen and it is removed by fractional distillation. Hydrogen is derived from methane (CH4) in a process called steam reforming.

Author: Francesca

Fran has taught A level Chemistry in the UK for over 10 years. As head of science, she used her passion for education to drive improvement for staff and students, supporting them to achieve their full potential. Fran has also co-written science textbooks and worked as an examiner for UK exam boards.

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