Limestone - Calcium Carbonate

HideShow resource information
  • Created by: Chloe
  • Created on: 13-11-12 18:25

Limestone - Calcium Carbonate

Limestone is mainly calcium carbonate, CaCO3, which when heated breaks down to form calcium oxide and carbon dioxide. Then calcium oxide reacts with water to produce calcium hydroxide. Limestone and its products have many uses, including being used to make cement, mortar and concrete.

1 of 6

Thermal decomposition

Calcium carbonate breaks down when heated strongly. This reaction is called thermal decomposition. Here are the equations for the thermal decomposition of calcium carbonate:

calcium carbonateright facing arrow with heat (http://www.bbc.co.uk/schools/gcsebitesize/science/images/arrow_heat.gif)calcium oxide + carbon dioxide

CaCO3right facing arrow with heat (http://www.bbc.co.uk/schools/gcsebitesize/science/images/arrow_heat.gif)CaO + CO2

Other metal carbonates decompose in the same way, including:

  • sodium carbonate
  • magnesium carbonate
  • copper carbonate
2 of 6

Thermal decomposition 2

Other metal carbonates decompose in the same way, including:

  • sodium carbonate
  • magnesium carbonate
  • copper carbonate

For example, here are the equations for the thermal decomposition of copper carbonate: copper carbonate right facing arrow with heat (http://www.bbc.co.uk/schools/gcsebitesize/science/images/arrow_heat.gif)copper oxide + carbon dioxide

CuCO3right facing arrow with heat (http://www.bbc.co.uk/schools/gcsebitesize/science/images/arrow_heat.gif)CuO + CO2

3 of 6

Making calcium hydroxide

Calcium oxide reacts with water to form calcium hydroxide, which is an alkali. Here are the equations for this reaction:

calcium oxide + water → calcium hydroxide

CaO + H2O → Ca(OH)2

4 of 6

Quarrying & Limestone causes pollution

Limestone is quarried (dug out of the ground) and used as a building material.

Digging limestone out the ground can cause enviromental problems:

  • It makes huge, ugly holes which permanently change the landscape.
  • When they blast rocks apart with explosive, make lots of noise and dust in quiet areas.
  • Destroys habitats of animals and birds.
  • Needs to be transported away from the quarry usually using lorries. This causes more noise and pollution.
  • Waste materials produce unsightly tips.

Making stuff from Limestone casues pollution too;

  • Cement factories make a lot of dust, which may cause breathing problems for some people.
  • Energy is needed to produce the cement and quicklime. The energy is most likely to come from burning fossil fuels, which cause pollution.
5 of 6

Advantages and Disadvantages of Limestone

The main advantages and disadvantages of the limestone industry

Advantages

  • Limestone is a valuable natural resource, used to make things such as glass and concrete.
  • Limestone quarrying provides employment opportunities that support the local economy in towns around the quarry.

Disadvantages

  • Limestone quarries are visible from long distances and may permanently disfigure the local environment.
  • Quarrying is a heavy industry that creates noise and heavy traffic, which damages people's quality of life.
6 of 6

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all The limestone cycle resources »