C1-Rocks

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Limestone

-Limestone's quarried out of the ground-it's great for making into blocks for building with.

-Limestone is mainly calcium carbonate. CaCO3

-Limestone goes through a cycle. 

  1. When it is heated it thermally decomposes to make calcium oxide and carbon dioxide.                        Calcium Carbonate--->Calcium Oxide+ Carbon Dioxide                                                                    CaCO3                       CaO                  CO2
  2. When you add water to calcium oxide you get calcium hydroxide.                                                       Calcium oxide+water---> Calcium hydroxide                                                                                   CaO                H2O         Ca(OH)2       
  3. Calcium hydorxide is an alkali which can be used to neutralise acidic soil in fields.
  4. Calcium Hydroxide can also be used to test for carbon dioxde. If you make a solution of calcium hydroxide in water (called limewater) and bubble gas through it, the solution will turn cloudy, if there;s carbon dioxide in the gas. The cloudiness is caused by the formation of calcium carbonate.                 Calcium hydroxide+ carbon dioxide--->calcium carbonate+water                                                     Ca(OH)2                  CO2                    CaCO3                   H2O    
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Limestone- Salts

  • Calcium Carbonate also reacts with acid to make calcium salt, carbon dioxide and water:          Calcium Carbonate+Sulfuric acid--->Calcium sulfate+carbon dioxide+water                                     CaCO3                    H2SO4             CaSO4               CO2                 H2O                                  
  • The type of salt produced depends on the type of acid. For example, a reaction with hydrochloric acid would make a chloride. 
  • Other carbonates that react with acids are magnesium, copper, zinc and sodium.
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Limestone Cycle

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Uses

  1. Powdered limestone is heated in a kiln with powdered clay to make CEMENT
  2. Cement can be mixed with sand and water to make mortar. Mortar is the stuff you stick bricks together with. You can use calcium hydroxide to mortar.
  3. Or you can mix cement with sand and aggregate (water and gravel) to make CONCRETE.
  4. Glass
  5. Reinforced concrete
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Quarrying Limestone

  1. Makes huge ugly holes-permenant 
  2. Makes a lot of noise and dust- in quite scenic areas.
  3. Destroys habitats 
  4. The limestone needs to be transported away from the quarry-usually in lorries. This causes more noise and pollution.
  5. Waste materials produce unsightly tips.
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Making stuff from Limestone

BAD

  1. Cement factories make a lot of dust, which can cause breathing problems.
  2. Energy is needed to produce cement and quicklime. The energy is likely to come from burning fossil fuels, which causes pollution. 

GOOD

  1. Provides things that people want-houses,roads. Chemicals used in making dyes, paints and medicenes
  2. Limestone products csn be used to neutalise acidic soil. Acidity in lakes and rivers caused by acid rain is also neutalised.
  3. Used in power station chimneys to neutralise sulfur dioxide, which is a cause of acid rain. 
  4. The quarry and assocaiated businesses provide jobs, and bring money into the local economy. 
  5. Landscaping and restoration of the area is normally requiresd as part of the planning permission
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Limestone Products: Advantages

-Limestone is widely available.

-Cheaper than granite or marble. 

-Easy rock to cut.

-Hardwearing, but also looks attractive.

-Concrete can be poured into moulds to make blocks or panels that can be joined together. It is very quick and cheap way of constructing buildings.

-Limestone,concrete, and cement do not rot when they get wet like wood does. They cannot be gnawed away by insects or rodents eithe. They are also fire resistant too. 

-Concrete does not corrode like lots of metals do. It can be reinforced with steel bars. 

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Limestone Products: Disadvantages

-Cocnrete is the most unattractive building material. 

-Concrete has a fairly low tensile strength and can crack.

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