In this I/GCSE Chemistry blog post, we will be looking at different carbonates.
Limestone (calcium carbonate - CaCO3) is used as a building material and in the manufacture of:
- Iron – in the blast furnace
- Glass – heated with sand and soda (sodium carbonate)
- Cement – heated with clay in a kiln
- Concrete/ mortar – mixed with sand and water (and crushed rock)
- Lime – thermal decomposition
Lime/ quicklime (calcium oxide - CaO) is made from limestone (calcium carbonate – CaCO3) by thermal decomposition.
Calcium carbonate CaCO3 + heat -----> calcium oxide CaO + carbon dioxide CO2
- Slaked lime (calcium hydroxide - Ca(OH)2) is formed by the reaction of calcium oxide and water which is very exothermic.
- The calcium carbonate in the limestone thermally decomposes to form calcium oxide (as above).
- This then reacts with silica (sand) impurities in the haematite
- Calcium oxide CaO(s) + silica SiO2(s) -----> calcium silicate CaSiO3(l)
This reaction is a neutralisation reaction.
- Calcium oxide is basic (as it is a metal oxide) and silica is acidic (as it is a non-metal oxide).
That is all!
References:
https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3D9LDG9cnGlDo&psig=AOvVaw17SfvTaLmHwcIYmyTheMx4&ust=1629130907050000&source=images&cd=vfe&ved=0CAsQjRxqFwoTCIiDk9y3s_ICFQAAAAAdAAAAABAD
https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.quora.com%2FWhat-are-some-uses-of-limestone&psig=AOvVaw152H8IPyvqMIHxJCWCoZ6D&ust=1629130967918000&source=images&cd=vfe&ved=0CAsQjRxqFwoTCICeqfe3s_ICFQAAAAAdAAAAABAD