Zinc Hydroxide Precipitation

ZnSO₄ + 2NaOH → Zn(OH)₂↓ + Na₂SO₄

Aperçu

Zinc sulfate reacts with sodium hydroxide to form a white gelatinous precipitate of zinc hydroxide (Ksp = 3.0 × 10⁻¹⁷). Zn(OH)₂ is amphoteric, dissolving in excess NaOH to form the zincate ion [Zn(OH)₄]²⁻. This amphoteric behavior is a diagnostic test for zinc in qualitative analysis.

Participants

Rôle	Substance	Coefficient	État
Réactif	Zinc Sulfate ZnSO₄	1	(aq)
Réactif	Sodium Hydroxide NaOH	2	(aq)
Produit	Sodium Sulfate Na₂SO₄	1	(aq)

Exemple du quotidien

Calamine lotion contains zinc compounds that form protective precipitates on skin, soothing itching from insect bites and rashes.

Importance industrielle

Zinc hydroxide precipitation is used in zinc recovery from wastewater, in calamine lotion production, and as a precursor to zinc oxide.

Propriétés

Type: Precipitation
Réversible: Non
Énergie: Exothermique
ΔH: -38,0 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 Zinc Hydroxide Precipitation?

The balanced equation is: ZnSO₄ + 2NaOH → Zn(OH)₂↓ + Na₂SO₄.

What type of reaction is Zinc Hydroxide Precipitation?

Zinc Hydroxide Precipitation is a precipitation reaction.

Is Zinc Hydroxide Precipitation exothermic or endothermic?

Zinc Hydroxide Precipitation is exothermic (releases energy). The enthalpy change (ΔH) is -38.0 kJ/mol.