Copper (I) oxide is a red or brown powder with the chemical formula Cu2O. It is used as a pigment, a catalyst, and in solar cells for its semiconducting properties.
| IUPAC Name | Copper(I) oxide |
| Molecular Formula | Cu2O |
| CAS Number | 1317-39-1 |
| Synonyms | Copper oxide, Cuprite, Dicopper oxide, Delafossite, Cuprous monoxide, Copper suboxide |
| InChI | InChI=1S/2Cu.O |
Cu2O molar mass
The molar mass of Cu2O is 143.09 g/mol. This value is calculated by adding the atomic weights of two copper atoms (63.55 g/mol x 2) and one oxygen atom (15.99 g/mol). The molar mass is an important property of a chemical compound that helps to determine the amount of substance present in a given sample. It is also used in stoichiometric calculations to determine the amount of reactants needed for a chemical reaction.
Cu2O boiling point
Cu2O does not have a boiling point as it decomposes before reaching its boiling point. When heated, it decomposes into copper metal and oxygen gas. The decomposition temperature of Cu2O is approximately 900°C. Therefore, Cu2O is primarily used as a solid-state material, such as a pigment or a semiconductor.
Cu2O melting point
The melting point of Cu2O is 1,232°C. This value is higher than most metals and metal oxides. Cu2O has a high melting point due to the strong ionic bond between the copper and oxygen atoms. The high melting point makes Cu2O useful in high-temperature applications, such as ceramic glazes and refractory materials.
Cu2O density g/ml
The density of Cu2O is 6.01 g/cm³. This value is higher than the density of copper metal (8.96 g/cm³) due to the presence of oxygen atoms. The high density of Cu2O makes it useful in various applications, such as in the manufacture of electrical conductors and semiconductors.
Cu2O molecular weight
The molecular weight of Cu2O is 143.09 g/mol. This value is calculated by adding the atomic weights of two copper atoms and one oxygen atom. The molecular weight of Cu2O is an important parameter for determining the physical and chemical properties of the compound. It is also used in stoichiometric calculations to determine the amount of reactants needed for a chemical reaction.
Cu2O structure
Cu2O has a crystal structure that is cubic in shape. The crystal structure of Cu2O is similar to that of rock salt (NaCl). The crystal lattice of Cu2O is composed of copper atoms that are coordinated with oxygen atoms in a 1:1 ratio. The crystal structure of Cu2O makes it a useful material in various applications, such as in the manufacture of semiconductors and catalysts.
Copper (I) oxide formula
The chemical formula of Copper (I) oxide is Cu2O. The formula indicates that Copper (I) oxide is composed of two copper atoms and one oxygen atom. The formula of Copper (I) oxide is used to determine the stoichiometry of chemical reactions involving Copper (I) oxide. It is also used to calculate the molar mass and molecular weight of the compound. The chemical formula of Copper (I) oxide is important in determining its physical and chemical properties, such as its color, melting point, and density.
| Appearance | Red or brown powder |
| Specific Gravity | 6.01 g/cm³ |
| Color | Red or brown |
| Odor | Odorless |
| Molar Mass | 143.09 g/mol |
| Density | 6.01 g/cm³ |
| Melting Point | 1,232°C |
| Boiling Point | Decomposes before boiling |
| Flash Point | Not applicable |
| Water Solubility | Insoluble |
| Solubility | Soluble in concentrated acids and ammonium hydroxide |
| Vapour Pressure | Not applicable |
| Vapour Density | Not applicable |
| PKa | Not applicable |
| PH | 8.0 – 9.0 (10% suspension in water) |
Copper (I) oxide Safety and Hazards
Cu2O is relatively safe to handle, but it should be handled with care due to its potential hazards. It is an irritant to the eyes, skin, and respiratory system. Direct contact with Cu2O powder can cause skin irritation, while inhalation of the powder can cause respiratory irritation. It is also a flammable solid and can ignite if exposed to heat or flame. Cu2O can react violently with certain substances, such as acids and halogens, and can release toxic gases. Adequate precautions should be taken when handling Cu2O, such as wearing protective clothing and avoiding contact with incompatible materials.
| Hazard Symbols | Xn: Harmful |
| Safety Description | S22: Do not breathe dust. S36/37/39: Wear suitable protective clothing, gloves and eye/face protection. S46: If swallowed, seek medical advice immediately and show this container or label. |
| UN Ids | UN3077 |
| HS Code | 28255000 |
| Hazard Class | 9 – Miscellaneous hazardous material |
| Packing Group | III |
| Toxicity | Low toxicity, but may cause irritation to the eyes, skin, and respiratory system upon direct contact or inhalation. |
Copper (I) oxide Synthesis Methods
There are various methods to synthesize Copper (I) oxide (Cu2O), including thermal oxidation, precipitation, electrochemical deposition, and chemical reduction.
Thermal oxidation involves heating Copper metal at high temperatures in the presence of oxygen or air to form Cu2O. The process can be carried out in a furnace or by flame oxidation.
Precipitation involves the reaction of copper salts with an alkaline solution, such as sodium hydroxide, to form Cu2O precipitates. The precipitates can be filtered, washed, and dried to obtain Cu2O powder.
Electrochemical deposition involves the electrolysis of a Copper salt solution using an inert electrode to deposit Cu2O on the electrode surface.
Chemical reduction involves the reduction of copper ions using a reducing agent, such as sodium borohydride or hydrazine, in the presence of a stabilizing agent, such as polyvinylpyrrolidone.
Another method involves the thermal decomposition of copper formate in the presence of a reducing agent, such as urea, to form Cu2O.
Each synthesis method has its advantages and disadvantages in terms of yield, purity, and scalability. It is important to carefully select the appropriate method based on the intended application and desired properties of Cu2O.
Copper (I) oxide Uses
Copper (I) oxide has a wide range of applications due to its unique properties, including its semiconductor behavior, catalytic activity, and antibacterial properties. Some common uses of Cu2O include:
- Electronics: Used as a p-type semiconductor material in electronic devices such as solar cells, photodetectors, and field-effect transistors.
- Catalyst: Used as a catalyst in various chemical reactions, such as the oxidation of carbon monoxide and the reduction of nitrogen oxides.
- Pigment: Used as a red pigment in ceramics, glasses, and enamels.
- Fungicide: Used as a fungicide to control plant diseases such as blight, mildew, and rust.
- Antifouling agent: Used as an antifouling agent in marine paints to prevent the growth of marine organisms on ships and offshore structures.
- Antibacterial agent: Has antibacterial properties. Used in medical applications such as wound dressings and antibacterial coatings.
- Additive: Used as an additive in animal feed to prevent copper deficiency in livestock.
The diverse range of applications of Cu2O demonstrates its potential as a valuable material in various industries.
Questions:
Q: Is copper (I) oxide hazardous when dry?
A: Cu2O is not considered hazardous when dry, but it can be a respiratory irritant when inhaled in powder form.
Q: Is copper (I) oxide a natural compound?
A: Yes, Cu2O is a natural compound that can be found in some minerals, such as cuprite and tenorite.
Q: What dissolves copper (I) oxide?
A: Cu2O is insoluble in water and most organic solvents. It can be dissolved in strong acids, such as hydrochloric acid, and in solutions of ammonia or potassium cyanide.
Q: What is the chemical method to make a copper (I) oxide layer on copper metal?
A: One chemical method to make a Cu2O layer on copper metal is to immerse the copper in a solution of copper sulfate and sodium chloride, and then heat the copper in the air to oxidize the surface.
Q: How can copper be extracted from copper (I) oxide?
A: Copper can be extracted from Cu2O by heating the compound with carbon or another reducing agent to reduce the Cu2O to metallic copper.
Q: How many moles of copper would be needed to make 1 mole of Cu2O?
A: 2 moles of copper would be needed to make 1 mole of Cu2O.
Q: What is Cu2O?
A: Cu2O is the chemical formula for copper (I) oxide, a red or brownish-red powder that is an oxide of copper.
Q: What happens when copper (I) oxide is present on a copper surface?
A: When copper (I) oxide is present on a copper surface, it can act as a protective layer against further oxidation and corrosion of the copper metal.