Limestone is quarried as it has many uses - it can be used for building as it is used to make calcium oxide and cement
Concrete - cement, sand, aggregate and water
Limestone - calcium carbonate CaCO3 - when heated -> decomposes -> calcium oxide (quicklime) and CO2 - this is done on a large scale in kilns and called thermal decomposition
CaCO3 -> CaO + CO2
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C1.2.2 - Reactions of Carbonates
Metal carbonates - react in similar ways when heated or with acids, decompose to metal oxide and CO2 when heated strongly enough - bunsen burners aren't hot enough to decompose sodium or potassium carbonate
Carbonate + acid -> salt + water + CO2
Limestone - damaged by acid rain - CaCO3 reacts with acid in the rain
Calcium hydroxide solution - limewater - used to test for CO2 - turns cloudy as reacts with CO2 to produce insoluable CaCO3
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C1.2.3 - The 'Limestone Reaction Cycle'
CaCO3 ->heat-> CaO + CO2
CaO + H2O -> Ca(OH)2
Ca(OH)2 + CO2 -> CaCO3
Calcium hydroxide - alikali - used to neutralise acids - used by farmers to neutralise soil and industry to neutralise gases, not very soluable in water - dissolves slightly to make limewater
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C1.2.4 - Cement and Concrete
Cement - limestone mixed with clay, heated strongly in kiln, ground into fine powder
Mortar - cement mixed with sand and water, used to hold bricks and blocks in buildings together
Concrete - aggregate, cement, sand and water, poured into moulds and then sets to form hard solid
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C1.2.5 - Limestone Issues
Limestone is needed for building - cement and concrete are used in most buildings
Disadv of limestone - - quarrying limestone - negative impacts on environment and people living near quarries - cement - uses lots of heat, therefore energy, large area of land needed - other issues - dust, noise, traffic, loss of habitat for wildlife
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