NPK fertilisers

• Why are fertilizers critical for modern farming?

  They replace elements taken up by plants
• What does NPK stand for in fertilizers?

  Nitrogen, Phosphorus, and Potassium
• How do compounds containing nitrogen, phosphorus, and potassium affect plants?

  They help plants grow larger and more rapidly
• What is the main compound of nitrogen in NPK fertilizers?

  Ammonium nitrate
• What is the formula for ammonium nitrate?

  NH₄NO₃
• How is ammonia produced for making ammonium nitrate?

  By the Haber process
• What is the process to produce ammonium nitrate from ammonia and nitric acid?

  Reacting ammonia with nitric acid
• What are the two main sources of potassium in NPK fertilizers?

  Potassium chloride and potassium sulfate
• How is phosphate rock processed for use in fertilizers?

  It must be chemically processed
• What does treating phosphate rock with nitric acid produce?

  Phosphoric acid and calcium nitrate
• Why can't phosphoric acid be added directly to plants?

  It needs to be neutralized with ammonia first
• What is produced when phosphate rock is treated with sulfuric acid?

  Single super phosphate
• What is the difference between single super phosphate and triple super phosphate?

  Single super phosphate is made with sulfuric acid, while triple super phosphate is made with phosphoric acid
• What is the main difference between industrial and lab production of ammonium nitrate?

  Industrial production is continuous, while lab production is batch
• How is ammonium nitrate produced in a school lab?

  By reacting dilute solutions of ammonia and nitric acid
• What is a key safety consideration in industrial production of ammonium nitrate?

  The heat produced must be safely removed
• How is crystallization achieved in the lab when producing ammonium nitrate?

  Using a water bath and a Bunsen burner
• What is the advantage of using the heat from the exothermic reaction in industrial processes?

  It provides energy for later stages of production
• What is the scale of production in industry compared to a lab for ammonium nitrate?

  Thousands of kilograms can be produced in industry
• What are the steps involved in producing ammonium nitrate in industry compared to a lab?

  • In industry:
  • Uses concentrated ammonia and nitric acid
  • Continuous process
  • Exothermic reaction heat is utilized
  • In lab:
  • Uses dilute solutions for safety
  • Batch process
  • Crystallization requires external heat
• What are the different treatments of phosphate rock and their products?

  1. With nitric acid:

  • Produces phosphoric acid and calcium nitrate

  1. With sulfuric acid:

  • Produces single super phosphate

  1. With phosphoric acid:

  • Produces triple super phosphate
• What are the key elements in NPK fertilizers?

  • Nitrogen
  • Phosphorus
  • Potassium