Limestone Reactions and Uses

When limestone is heated strongly, it breaks up. Calcium carbonate decomposes to form calcuim oxide and carbon dioxide.

Calcium Carbonate ----> Calcium Oxide + Carbon Dioxide

CaCO3 ----> CaO + CO2

Other metals compounds can thermally decompose such as Copper Carbonate.

Calcium oxide reacts with water which forms Calcium Hydroxide.

Calcium Oxide + Water ----> Calcium Hydroxide

CaO + H2O ----> Ca(OH)2

Use:

• Neutralisation of acidity (eg. in soil and lakes)

Carbonates and acids create Carbon Dioxide, Salt, and Water.

For example:

Calcium Carbonate + Hydrochloric acid ----> Carbon Dioxide + Calcium Chloride + Water

CaCO3 + 2HCl ----> CO2 + CaCl2 + H2O

Calcium carbonate (Limestone) is dissolved by acid rain in this way.

Cement:

• Heat powdered limestone with clay.
• It is an ingredient in Mortar and Concrete...

Mortar:

• Mix cement with sand and water.

Concrete:

• Mix cement with sand, water and gravel.

Advantages:

• Limestone is valueable: used to make glass and concrete.
• Quarries provide job opportunities.
• The jobs support the local economy.

Disadvantages:

• Quarries are noisy and create heavy traffic, lowering the locals' quality of life.
• They perminantly scar the landscape.
• Quarrying vehicles create pollution in the area.

Advantages and disadvantages of limestone as building material.

Limestone, cement and mortar slowly react with carbon dioxide in acid rain (which is made worse by added pollution). Limestone looks very attractive.

Concrete can be molded before it sets. It's strong when pushed but weak when bent or stretched. It can be reinforced with steel pillars. Concrete builds don't look attractive.