Limestone Cycle

Limestone: It's Cycle, Uses, Advantages and Disadvantages.

Limestone's chemical name is Calcium Carbonate.

Its chemical formula is CaCO3 - which means it has:

• 1 calcium atom,
• 1 Carbon atom,
• and 3 Oxygen atoms.

It is quarried out of the ground so it can be used for building materials such as cement.

Limestone can be used to make:

• Mortar: Cement + Sand + Water = Mortar, 
• Concrete: Cement + Sand + Aggregate + Water  = Concrete,
• Cement: Calcium Oxcide + Powdered clay + Water = Cement
• And Glass

Other uses are: 

• Another use for it is for purifying iron in blast furnaces. 
• It can also be used to neutralise the acid in lakes and land.

Calcium Oxide:

Stage one of this process is creating Calcium Oxide.

1) Calcium Carbonate when heated, thermal decomopsition, becomes Calcium Oxide and Carbon Dioxide.

Calcium Carbonate = Calcium Oxide + Carbon Dioxide.

CaCO3 = CaO + CO2

Calcium oxide is also called Quicklime. 

This resource, Quicklime, can be used to make lime mortar, cement and concrete.

Calcium Hydroxide:

Stage two of this process if creating Calcium Hydroxide.

1) Calcium Oxide when added to water becomes Slake lime/ Calcium Hydroxide

Calcium oxide + water = calcium hydroxide

CaO + H₂O = Ca(OH)_2(s)

Caclium Hydroxide is an alkali. This means that it can be used to neutralise acids.

This can be used by farmers to neutralise acidic soil in their land.

Calcium Hydroxide Soultion:

Stage three of this process is creating Calcium Hydroxide.

3) Slake Lime / Calcium Hydroxide when water is added becomes Limewater/ Calcium Hydroxide solution.

Calcium Hydroxide + Water = Calcium Hydroxide

Ca(OH)₂  + H₂O = Ca(OH) _2(aq)

Lime water is used to test for Carbon Dioxide. This is done by adding the gas to   the Calcium Hydroxide Solution. If the gas is Carbon Dioxide, the Calcium Hydroxide Solution will turn cloudy. 

This is called the Limewater test.  

Calcium Carbonate:

Stage four of this process is creating Calcium Carbonate.

4) Slake lime/ Calcium Hydroxide solution when Carbon Dioxide is added becomes Calcium Carbonate and water.

Calcium Hydroxide + Carbon Dioxide = Calcium Carbonate + Water

Ca(OH)_{2 (aq)} + CO₂ = CaCO₃ + H₂O 

And now we have reached the end of the cycle. 

Advantages:

• It makes new Jobs for people.
• It increases income as workers need places to live, shop..
• It creates materials.
• Limestone is a valuable natural resource, which could be used to make things such as glass and concrete for the nearby towns are country as a whole. 

Disadvantages

• Limestone, cement and mortar all will react with acid rain and erode away over time. This means that there will be damages in the walls and other areas in 
• Some people think concrete building and bridges are unattractive.
• Limestone quarries  may perminatly ruin landscapes and are eyesores as they can be seen from long distances.
• Quarrying will create noise pollution and air pollution (dust). 
• Quarrying will create traffic on roads that are used to transport the limestone.