Preparation of Calcium Carbonate
Details
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Calcium Carbonate has the formula CaCO3 . It is a white colored substance. It is found numerous minerals in Earth's crust, like Calcite, Chalk, Limestone, etc. It is basic in nature and reacts with many acids to form Calcium salts. It is insoluble in water but dissolves and reacts with acids.
Requirements
- Powdered Blackboard chalk (containing Calcium Sulfate; CaSO4)
- Water
- Heat source
- Beaker
- Sodium Carbonate = Na2CO3
Process
- Take water in a beaker and heat it till it is hot, but not boiling.
- Completely dissolve required amount of Sodium carbonate in it.
- Take same amount of Powdered Blackboard chalk, and add it slowly to the hot Na2CO3 solution.
- There might be some fizzing and the solution will become cloudy.
- The cloudiness is due to Calcium carbonate. Let the precipitate sit down for some time.
- Filter the solution, and obtain the white CaCO3 residue.
Observations
When we add Calcium sulfate to a solution of Sodium carbonate a double displacement reaction takes place:
Na2CO3 + CaSO4 = CaCO3 + Na2SO4
The white precipitate is Calcium carbonate, which is water-insoluble. There might be some fizzing because of impurities in chalk powder. The left over solution contains Sodium sulfate, along with some impurities.
Na2CO3 + CaSO4 = CaCO3 + Na2SO4
The white precipitate is Calcium carbonate, which is water-insoluble. There might be some fizzing because of impurities in chalk powder. The left over solution contains Sodium sulfate, along with some impurities.