| IUPAC name
| Other names
Red copper oxide
|Molar mass||143.09 g/mol|
|Melting point||1,232 °C (2,250 °F; 1,505 K)|
|Boiling point||1,800 °C (3,270 °F; 2,070 K)|
|Solubility|| Reacts with acids, aq. NH3|
Insoluble in alcohols, ethers, halocarbons, hydrocarbons
|Vapor pressure||~0 mmHg|
Std enthalpy of
|Safety data sheet||Sigma-Aldrich|
|Lethal dose or concentration (LD, LC):|
LD50 (Median dose)
|1.340 mg/kg (rat, oral)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Copper(I) oxide or cuprous oxide is the inorganic compound with the formula Cu2O.
Copper(I) oxide degrades to copper(II) oxide in moist air.
- Cu2O + ½ O2 → 2 CuO
Copper(I) oxide dissolves in concentrated aq. ammonia solution to form the colorless complex [Cu(NH3)2]+, which is easily oxidized in air to the blue [Cu(NH3)4(H2O)2]2+. It dissolves in hydrochloric acid to give solutions of CuCl2−.
Cuprous oxide is a reddish brown solid, odorless, insoluble in solvents.
Is is sold by chemical suppliers. Can also be bought online.
Reduction of copper(II) solutions with sulfur dioxide will yield this compound.
Aqueous cuprous chloride solutions react with base like sodium hydroxide to give copper(I) oxide.
In all procedures, the color of the product is highly sensitive to the procedural details.
- Copper compound collecting
- Make copper metal
- Make copper complexes
Copper(I) oxide is an irritant, so avoid handling it directly.
Copper(I) oxide should be kept in air-tight bottles.
Reduce it to metallic copper with a reducing agent.