Question

On heating, calcium carbonate get converted in calcium oxide and carbon dioxide.
a.) Is this a physical or chemical change
b.) Can you prepare one acidic and one basic solution by using the products formed in the above process, write the chemical equation involved?

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Answer 1

a) This is a chemical change.

Heating limestone to over 900 degree C under goes thermal decomposition to produce calcium oxide and carbon dioxide.

limestone ==> quicklime + carbon dioxide

calcium carbonate ==> calcium oxide + carbon dioxide

CaCO3(s) ==> CaO(s) + CO2(g)

b) Acidic and basic solutions can be prepared by dissolving products of the above process in water.

CaO + H2O -------> Ca(OH)2 (basic solution)

Calcium oxide + water-----------> calcium hydroxide (basic solution)

CO2 + H2O ----------> H2CO3 (acidic solution)

Carbon dioxide + water --------> Carbonic acid (acidic solution)