Calcium Carbonate Precipitation

CaCl₂ + Na₂CO₃ → CaCO₃↓ + 2NaCl

Aperçu

Calcium chloride reacts with sodium carbonate to precipitate calcium carbonate. CaCO₃ has a Ksp of 3.4 × 10⁻⁹. This is the fundamental reaction behind water softening, where dissolved calcium (hardness) is removed as insoluble carbonate. The precipitate is a white powder.

Participants

Rôle	Substance	Coefficient	État
Réactif	Sodium Carbonate Na₂CO₃	1	(aq)
Produit	Calcium Carbonate CaCO₃	1	(s)
Produit	Sodium Chloride NaCl	2	(aq)

Exemple du quotidien

Limescale buildup in kettles and pipes is calcium carbonate precipitated from hard water when heated or evaporated.

Importance industrielle

Precipitated calcium carbonate (PCC) is used as a paper filler, in paints, plastics, and pharmaceuticals. Water softening by carbonate precipitation is a major industrial process.

Propriétés

Type: Precipitation
Réversible: Non
Énergie: Exothermique
ΔH: -13,0 kJ/mol

Réactions associées

Aluminum Hydroxide Precipitation Barium Sulfate Precipitation Cadmium Sulfide Precipitation (Yellow) Calcium Phosphate Precipitation (Bone Mineral) Chromium(III) Hydroxide Precipitation Lead Carbonate Precipitation Magnesium Hydroxide Precipitation Copper Sulfide Precipitation Cobalt(II) Hydroxide Precipitation Iron(III) Hydroxide Precipitation

Frequently Asked Questions

What is the equation for Calcium Carbonate Precipitation?

The balanced equation is: CaCl₂ + Na₂CO₃ → CaCO₃↓ + 2NaCl.

What type of reaction is Calcium Carbonate Precipitation?

Calcium Carbonate Precipitation is a precipitation reaction.

Is Calcium Carbonate Precipitation exothermic or endothermic?

Calcium Carbonate Precipitation is exothermic (releases energy). The enthalpy change (ΔH) is -13.0 kJ/mol.