Calcium Sulfate Precipitation (Gypsum)

Ca(NO₃)₂ + Na₂SO₄ → CaSO₄↓ + 2NaNO₃

Aperçu

Calcium nitrate reacts with sodium sulfate to precipitate calcium sulfate (Ksp = 4.9 × 10⁻⁵). CaSO₄ is sparingly soluble, not truly insoluble. The dihydrate form (CaSO₄·2H₂O) is gypsum, one of the most important construction materials. Plaster of Paris is the hemihydrate form.

Participants

Rôle	Substance	Coefficient	État
Réactif	Sodium Sulfate Na₂SO₄	1	(aq)
Produit	Calcium Sulfate CaSO₄	1	(s)
Produit	Sodium Nitrate NaNO₃	2	(aq)

Exemple du quotidien

Drywall (gypsum board) used in nearly every building contains calcium sulfate dihydrate, produced by similar precipitation chemistry.

Importance industrielle

Gypsum production exceeds 250 million tonnes annually for drywall, plaster, cement, and soil amendment. FGD gypsum from power plants is increasingly important.

Propriétés

Type: Precipitation
Réversible: Non
Énergie: Exothermique
ΔH: -8,0 kJ/mol

Réactions associées

Aluminum Hydroxide Precipitation Barium Carbonate Precipitation Barium Sulfate Precipitation Cadmium Sulfide Precipitation (Yellow) Calcium Fluoride Precipitation (Fluorite) Calcium Phosphate Precipitation (Bone Mineral) Chromium(III) Hydroxide Precipitation Lead Carbonate Precipitation Lead Chloride Precipitation Iron(III) Hydroxide Precipitation

Frequently Asked Questions

What is the equation for Calcium Sulfate Precipitation (Gypsum)?

The balanced equation is: Ca(NO₃)₂ + Na₂SO₄ → CaSO₄↓ + 2NaNO₃.

What type of reaction is Calcium Sulfate Precipitation (Gypsum)?

Calcium Sulfate Precipitation (Gypsum) is a precipitation reaction.

Is Calcium Sulfate Precipitation (Gypsum) exothermic or endothermic?

Calcium Sulfate Precipitation (Gypsum) is exothermic (releases energy). The enthalpy change (ΔH) is -8.0 kJ/mol.