Carbonates

5.3 Rusting

5.5 Environmental problems

Carbonates

  1. Thermal decomposition

    1. The carbonates of magnesium, copper, zinc, calcium and lithium thermally decompose into their respective oxide and carbon dioxide
    2. Not all Group I metal carbonates decompose at the temperatures reached by a Bunsen burner

  2. Calcium carbonate

    1. Limestone, which contains calcium carbonate CaCO3, is quarried and can be used as a building material, or powdered and used to control acidity in soil
    2. Calcium carbonate thermally decomposes into calcium oxide: CaCO3 (s) → CaO(s) + CO2 (g), known as quicklime which is important in the manufaction of cement, glass and extracting iron
    3. Calcium oxide reacts with water to form calcium hydroxide: CaO(s) + H2O(l) → Ca(OH)2 (aq), known as limewater, which can be used to test for carbon dioxide
    4. Limewater reacts with carbon dioxide to produce calcium carbonate: Ca(OH)2 (aq) + CO2 (g) → CaCO3 (s) + H2O(l)