- Limestone is quarried out of the ground and is used for making buildings.
- Limestone is mainly calcium carbonate - CaCO3.
- When it's heated it thermally decomposes to make calcium oxide and carbon dioxide. The equation for this is:
CaCO3 = CaO + CO2
- When magnesium, copper, zinc and sodium carbonates are heated they decompose in the same way.
- Calcium carbonate also reacts with acid to make a calcium salt, carbon dioxide and water.
CaCO3 + H2SO4 = CaSO4 + CO2 + H20
When calcium carbonate reacts with an acid it always makes carbon dioxide and water.
When you add water to calcium oxide you produce calcium hydroxide.
CaO + H20 = Ca(OH)2
- Calcium hydroxide is an alkali so can be used to neutralise acidic soil in fields.
- Powdered limestone can also be used, the the advantage of using calcium hdroxide is that is works much faster.
- Calcium hydroxide can be used to test for carbon dioxide too. If you make a solution of calcium hydroxide in water (limewater) and bubble gas…