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Key Questions:

1. The Haber process is used to manufacture what substance?
   • The Haber process is used to manufacture ammonia, which can be used to produce nitrogen-based fertilisers.
2. Write a word equation for the Haber process?
   • Nitrogen Hydrogen <=> Ammonia
3. Why does some of the ammonia produced through the Haber process break back down into nitrogen and hydrogen?
   • Because the reaction is a reversible reaction.
4. Explain how the commercially used conditions for the Haber process are related to the availability and cost of raw materials?
   • The raw materials for this process are hydrogen and nitrogen. Hydrogen is obtained by reacting natural gas - methane - with steam, or through the cracking of oil. This pathway is used as hydrocarbon compounds contain large percentages of hydrogen and are readily available. Nitrogen is obtained by burning hydrogen in air. Air is used due to being rich in Nitrogen gas (79% nitrogen); nearly all the rest is oxygen. When hydrogen is burned in air, the oxygen combines with the hydrogen, leaving nitrogen behind.
5. How is any ammonia created through the Haber process separated from any unreacted nitrogen and hydrogen?
   • The remaining products are cooled. Ammonia has a much higher boiling point than either hydrogen or nitrogen, so liquefies and is removed. The remaining hydrogen and nitrogen gases are recycled.
6. Justify why the Haber process is carried out at 200 atmospheres?
   • The Haber process is a reversible reaction meaning it will reach a dynamic equilibrium As there are fewer molecules of product than reactant, high pressure pushes equilibrium to favour the products and produce a higher yield of ammonia. The reason pressures higher than 200 atmospheres are not used - Substances under extremely high pressure can be dangerous. - Extremely expensive equipment must be used to keep reactants under sustained high pressures. - High amounts of Energy are required to pressurise the gas.
7. Justify the use of a high temperature in the Haber process?
   • The Haber process is a reversible reaction meaning it will reach a dynamic equilibrium The forward reaction is exothermic, so in fact a higher temperature reduces the yield of ammonia. The reason that higher temperatures are used are to increase the rate of reaction, to make the process economically viable.
8. Suggest why a catalyst is used in the Haber process?
   • The Haber process is a reversible reaction meaning it will reach a dynamic equilibrium. The use of a catalyst does not affect the position of equilibrium, but will speed up the rate at which it reaches equilibrium.
9. What are the raw materials required for the Haber process?
   • The raw materials for the Haber process are nitrogen and hydrogen
10. What is commonly used as the source of nitrogen in the Haber process? What is commonly used as the source of hydrogen in the Haber process?
    • Nitrogen gas used in the reaction is taken from the air by reacting the oxygen in the air with hydrogen, leaving nearly pure hydrogen gas. Hydrogen for the reaction is created by reacting natural gas (mostly methane) and steam.
11. What conditions are used in the Haber process?
    • - Iron catalyst - High temperature (450C) - High pressure (200 atmospheres)