What is Cuprous Oxide?

Cuprous oxide is a monovalent copper oxide, appearing as a bright red powdery solid. It is almost insoluble in water, disproportionates into divalent copper and elemental copper in acidic solutions, and gradually oxidizes to black copper oxide in humid air.
Basic Information
• Molecular Formula: Cu2O
• Molecular Weight: 143.0914
• CAS Registry Number: 1317-39-1
• EINECS: 215-270-7
• Molecular Structure: Cu-O-Cu
• Melting Point: 1232ºC
Applications
1. Marine & Antifouling
Used in the manufacture of marine antifouling paints (to kill lower marine organisms).
2. Agriculture
Used to prepare agricultural fungicides. It is widely applied to control downy mildew and anthracnose in fruit trees (such as citrus and grapes), as well as rice blast, making it an important variety among inorganic copper preparations at present. 
3. Ceramics & Glass
Used as a red colorant, it imparts a bright red color to glass, enamel and ceramic glazes.
4.Other
It is also applied in the preparation of copper plating and copper alloy plating solutions.