Copper(II) Hydroxide Precipitation
CuSO4 + 2NaOH → Cu(OH)2↓ + Na2SO4
Overview
Copper sulfate reacts with sodium hydroxide to form a pale blue gelatinous precipitate of copper(II) hydroxide (Ksp = 2.2 × 10⁻²⁰). The precipitate can be dehydrated by heating to produce black copper(II) oxide. This reaction is the basis of the Biuret test for proteins.
Participants
| Role | Substance | Coefficient | State |
|---|---|---|---|
| Reactant | Copper(II) Sulfate CuSO₄ | 1 | (aq) |
| Reactant | Sodium Hydroxide NaOH | 2 | (aq) |
| Product | Sodium Sulfate Na₂SO₄ | 1 | (aq) |
Everyday Example
The Biuret test for proteins uses Cu(OH)₂ formed from copper sulfate and NaOH; proteins turn the mixture violet due to copper-peptide bond complexation.
Industrial Importance
Copper hydroxide is used as a fungicide (Bordeaux mixture), in copper electroplating solutions, and as a precursor to copper oxide catalysts.
Properties
- Type
- Precipitation
- Reversible
- No
- Energy
- Exothermic
- ΔH
- -59.0 kJ/mol
Related Reactions
Aluminum Hydroxide Precipitation
Barium Carbonate Precipitation
Barium Sulfate Precipitation
Cadmium Sulfide Precipitation (Yellow)
Calcium Carbonate Precipitation
Calcium Fluoride Precipitation (Fluorite)
Calcium Oxalate Precipitation (Kidney Stones)
Calcium Phosphate Precipitation (Bone Mineral)
Calcium Sulfate Precipitation (Gypsum)
Chromium(III) Hydroxide Precipitation
Frequently Asked Questions
What is the equation for Copper(II) Hydroxide Precipitation?
The balanced equation is: CuSO₄ + 2NaOH → Cu(OH)₂↓ + Na₂SO₄.
What type of reaction is Copper(II) Hydroxide Precipitation?
Copper(II) Hydroxide Precipitation is a precipitation reaction.
Is Copper(II) Hydroxide Precipitation exothermic or endothermic?
Copper(II) Hydroxide Precipitation is exothermic (releases energy). The enthalpy change (ΔH) is -59.0 kJ/mol.