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Production of fertilisers

A major use of ammonia is in the manufacture of fertilisers. The most effective fertilisers contain nitrogen because plants need it in order to produce proteins. Phosphorus and potassium are also essential elements commonly found in fertilisers. Using artificial fertilisers has advantages and disadvantages.

Advantages

• Increases crop growth.
• Increases crop yield.
• Better soil quality.

Disadvantages

• Causes eutrophication.
• Causes blue baby syndrome.
• Turns the soil acidic.

Many fertilisers are ammonium salts. They can also be made from ammonium hydroxide (ammonia solution). If ammonium hydroxide is used, water is also produced in the neutralisation reaction.

Ammonia + nitric acid → ammonium nitrate

NH₃ + HNO₃ → NH₄NO₃

Ammonium hydroxide + nitric acid → ammonium nitrate + water

NH₄OH + HNO₃ → NH₄NO₃ + H₂O

Ammonia + sulfuric acid → ammonium sulfate

2NH₃ + H₂SO₄ → (NH₄)₂SO₄

Ammonium hydroxide + sulfuric acid → ammonium sulfate + water

2NH₄OH + H₂SO₄ → (NH₄)₂SO₄ + H₂O