Breaking down a compound to simpler compounds or elements using heat
As the calcium carbonate is heated
It decomposes to form calcium oxide and carbondioxide
how do you prove the gas produced is CO2
Bubbling it through limewater, which will turn milky if carbon dioxide is present
Stability of metal carbonates
More reactive the metal, the more stable the carbonate
Copper carbonate is fairly unstable and decomposes at a relatively low temperature
Sodium carbonate is very stable and does not decompose at the highest temperature which can be reached using a Bunsen burner flame
Uses of limestone
Manufacturing iron
Manufacturing steel
Road building
Making cement
Neutralisingacidic soil
What is Limestone
Calciumcarbonate (CaCO3)
What is Quicklime
Calciumoxide (CaO)
what is Slaked lime
Calciumhydroxide(Ca(OH)2)
The limestone cycle
1. Roast the limestone for 20 minutes
2. Add drops of water to the quicklime
3. Slaked lime can be converted back to calcium carbonate by adding carbon dioxide
During reaction 1 (roasting the limestone) we will observe the limestone shining orange
During reaction 2 (adding drops of water to the quicklime) we will observe whistling or hissing and the solid crumbling. This is an example of exothermic reaction
Advantages of quarrying for limestone
Provides materials for the construction industry
More local jobs
Creates more wealth for the community
Build better road systems
Disadvantages of quarrying for limestone
Dust from lorries and explosions
Spoils the landscape
Noise of explosions
Destruction of habitats
What is the chemical equation for calcium carbonate being heated?
CaCO3 -> CaO + CO2
What is the chemical equation to produce quicklime?
CaO + H2O -> Ca(OH)2
What is the chemical equation to produce slaked lime?
Ca(OH)2 + CO2 -> CaCO3 + H2O
What is calcium hydroxide (slaked lime) used for?
neutralisesacidityinlakesandsoil
What is observed when limestone is heated?
orange glow
what type of reaction is it when limestone is heated?
endothermic
what type of reaction is it when water is added to calcium oxide?
exothermic
What is produced when calcium hydroxide dissolves in excess water?
calcium hydroxide solution (limewater)
what happens when carbon dioxide reacts with calcium hydroxide (limewater)?
whitecalciumcarbonate is formed turning the limewater milky