Calcium Sulfate Precipitation (Gypsum)

Ca(NO3)2 + Na2SO4 → CaSO4↓ + 2NaNO3

Übersicht

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.

Teilnehmer

Rolle Substanz Koeffizient Zustand
Reaktant Sodium Sulfate Na₂SO₄ 1 (aq)
Produkt Calcium Sulfate CaSO₄ 1 (s)
Produkt Sodium Nitrate NaNO₃ 2 (aq)

Alltägliches Beispiel

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

Industrielle Bedeutung

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

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.