Uses of Group 2
- Three different calcium compounds are used commonly in agriculture, construction and iron extraction:
- Limestone - this is impure calcium carbonate
- Quicklime - this is calcium oxide, formed by the thermal decomposition of calcium carbonate
- Slaked lime - this is calcium hydroxide formed when water is added to quicklime
- All three materials are used in agriculture to raise the pH of the soil
- Over time, the soil becomes more acidic while the optimum pH for many crops to grow is at around 6-6.5
- The compounds are all bases and react with the acids in the soil and raise the pH of the soil
- Calcium carbonate is more commonly used in agricultural lime as it is cheaper and safer to handle
- However, due to calcium carbonate being largely insoluble, it acts more slowly than calcium hydroxide
