1. Unit 13: Chemical Industry

2. 13.1 hand-out

3. 13.2 Fertilizers

4. Plants! Plants don’t only need CO2, light, & H2O
They need Nitrogen to make amino acids & proteins
Can’t really get it from the air (can’t utilize N2)
Get it from the soil as nitrates or ammonium salts
Farmed crops remove N from the soil
Phosphorus & Potassium too
Must be replaced

5. Fertilizers
Fertilizer: substance added to the soil to replace the elements taken up by plants.
Also increases the crop yields
Animal Manure – natural fertilizer
Artificial Fertilizer: Replace lost nitrogen, phosphorus, and potassium
NPK Fertilizers

6. Fertilizers
Compound Fertilizer: may contain ammonium nitrate, ammonium phosphate, and potassium chloride
Single Fertilizer: Only ammonium nitrate

7. Making Fertilizers
~10% of the chemical industry is involved in making fertilizers.
Haber Process: chemical reactions that yield ammonia
Contact Process: chemical reactions that yield sulfuric acid
Potassium comes from salts that are mined

8. Displacement of Ammonia
Fertilizers are slightly acidic
Farmers add lime to the soil
Lime reacts with water to form slaked lime, Calcium Hydroxide (alkaline).
If too much lime is put in the soil, it reacts with the ammonium salts in fertilizers to release ammonia (not good).

9. Displacement of Ammonia
Ammonium + Calcium  Ammonia + Calcium + water Chloride Hydroxide Chloride 2NH4Cl(aq) + Ca(OH)2  2NH3(g) + CaCl2(aq) + H20(l)

10. 13.3 Limestone Industry

11. Limestone Main source of limestone is calcium carbonate A rock
Formed millions of years ago from the remains of sea creatures

12. Lime
Thermal Decomposition: compounds break down when heated, forming two or more products from one reactant
Heated limestone breaks down into calcium oxide (lime) and carbon dioxide
calcium carbonate → calcium oxide + carbon dioxide
CaCO3 → CaO + CO2

13. Making Lime
Lime is made by heating limestone in a rotary kiln.

14. Slaked Lime Slaked Lime: name for Calcium Hydroxide
Made from lime by adding water slowly.
Calcium Oxide + Water  Calcium Hydroxide
Solution of slacked lime is called limewater 

15. Uses of Limestone Products
Limestone Uses:
Building
Extraction of Iron
Construction of Roads
Manufacture of Cement

16. Uses of Lime Lime & Slacked Lime Uses:
Treatment of excess acidity in soils & Lakes
Neutralizing acidic industrial waste products, e.g. flue gas desulfurization. Removes sulfur dioxide from burning coal.