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Uses of fertilisers and the Haber process

Fertilisers

In this chapter you will learn:

  1. What are fertilisers?

  2. What is haber process?

What are fertilisers?

  • Fertilisers are chemicals that are added to the soil to increase crop production.

  • Fertilisers prevent future crops suffering from mineral deficiency.

  • Fertilisers are water soluble mineral that plants can absorb through the root.

  • Fertilisers improve the growth of crops.

  • The disadvantage of using too much fertilisers is that it can pollute water some time.

  • These fertilisers have plant nutrients, such as nitrogen, phosphorus, and potassium.

  • Ammonium nitrate, NH4NO3, is a salt used in fertilizers.

  • Ammonium nitrate is highly soluble in water

  • Ammonium ions, NH4+, and nitrate ions, NO3-, are important sources of soluble nitrogen.

  • Potassium chloride and potassium sulfate can be used as fertilisers because they contain potassium ions. Potassium chloride and potassium sulfate are obtained by mining.

  • Phosphate rock can be used to make fertilisers.

The Haber process

  • The Haber process is named after the German chemist, Fritz Haber. Ammonia is produced using the Haber process.

  • The raw materials for the Haber process are nitrogen and hydrogen.

  • In the Haber process: nitrogen and hydrogen are pumped through pipes.

  • The purified gases are passed over a catalyst of iron at a high temperature about 450°C and a high pressure about 200 atmospheres.

  • Some of the hydrogen and nitrogen reacts to form ammonia. The reaction is reversible; so, some of the ammonia produced breaks down into nitrogen and hydrogen.

  • When the mixture is cooled, the ammonia liquefies and it can be removed. Unreacted hydrogen and nitrogen are recycled.

  • The Haber process uses a catalyst to speed up the reaction. Because catalyst provides an alternative reaction pathway which has a lower activation energy.

  • One reason people might not want an ammonia factory near their town because of harmful to health and risk of explosion . ...........................................................................................................................

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