Chromium(III) Hydroxide Precipitation

CrCl3 + 3NaOH → Cr(OH)3↓ + 3NaCl

Übersicht

Chromium(III) chloride reacts with sodium hydroxide to form a green gelatinous precipitate of chromium(III) hydroxide (Ksp = 6.3 × 10⁻³¹). Cr(OH)₃ is amphoteric, dissolving in both excess acid and excess NaOH. In excess NaOH, it forms the green chromite ion [Cr(OH)₄]⁻.

Teilnehmer

Rolle Substanz Koeffizient Zustand
Reaktant Sodium Hydroxide NaOH 3 (aq)
Produkt Sodium Chloride NaCl 3 (aq)

Alltägliches Beispiel

The green color of some gemstones like emerald is due to chromium(III) ions, the same oxidation state that produces this green precipitate.

Industrielle Bedeutung

Chromium(III) hydroxide precipitation is used in chromium removal from industrial wastewater, particularly from chrome plating and leather tanning effluents.

Eigenschaften

Typ
Precipitation
Reversibel
Nein
Energie
Exotherm
ΔH
-90,0 kJ/mol

Verwandte Reaktionen

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

Frequently Asked Questions

What is the equation for Chromium(III) Hydroxide Precipitation?
The balanced equation is: CrCl₃ + 3NaOH → Cr(OH)₃↓ + 3NaCl.
What type of reaction is Chromium(III) Hydroxide Precipitation?
Chromium(III) Hydroxide Precipitation is a precipitation reaction.
Is Chromium(III) Hydroxide Precipitation exothermic or endothermic?
Chromium(III) Hydroxide Precipitation is exothermic (releases energy). The enthalpy change (ΔH) is -90.0 kJ/mol.