What Is Cupric Oxide Definition Formula Reactions and Uses in Chemistry
Cupric oxide is an inorganic chemical compound composed of cuprous ion and oxide ion. Cupric cuprous are the two forms of copper ions. Copper exists in two types of oxide, the one is with a higher oxidation state and another one is with a lower oxidation state, cupric oxide and cuprous oxide respectively.
Cupric Oxide and Cuprous Oxide
The oxides of copper are of two types:
Cupric oxide- It is also known as copper cupric oxide. The oxidation state of copper in this compound is +2. +2 is the highest oxidation state of copper. Generally, in short, you can write it as oxide cupric. It exists in the monoclinic crystal system.
Cuprous oxide- the oxidation state of copper in this compound is +1. +1 is the intermediate oxidation state of copper. It can easily get oxidised or reduced.
The oxides of cupric cuprous are represented as CuO and Cu2O respectively.
Preparation of Cupric Oxide and Cuprous Oxide
Cupric Oxide can be prepared by the following methods:
It can be produced by the thermal decomposition of the cupric carbonate.
CuCO3 → CuO + CO2
The thermal decomposition of cupric carbonate forms cupric oxide as a product and carbon dioxide gas as a byproduct.
Another method of Cupric oxide preparation is heating copper in the presence of air at a high temperature (around 300-800 degrees celsius).
Cu + O2 → CuO
Heating Copper Nitrate- The nitrate of copper is thermally unstable. On heating copper nitrate at a temperature around 180 degrees celsius.
2Cu (NO3)2 → 2 CuO + O2 + 4 NO2 (this reaction takes place at a temperature around 180 degrees celsius)
Heating Cupric Hydroxide- cupric hydroxide is a thermally unstable compound. It gets easily decomposed into cupric oxide on heating.
Cu(OH)2 → CuO + H2O
Properties of Cupric Oxide
Physical Properties of Cupric Oxide
Cupric oxide is a black colour compound.
Cupric oxide exists in powder (amorphous) form.
The melting point of cupric oxide is 1326 degrees celsius.
Cupric oxide is insoluble in water.
Cupric oxide is soluble in ammonium chloride and potassium cyanide.
Chemical Properties of Cupric Oxide
Cupric acid reacts with strong mineral acids like hydrochloric acid (HCl), sulphuric acid (H2SO4), and nitric acid (HNO3) to form salts.
CuO + HNO3 → Cu (NO3)2 + H2O
CuO + 2HCl → CuCl2 + H2O
CuO + H2SO4 → CuSO4 + H2O
Cupric oxide reacts with the concentrated base and forms salt.
2KOH + CuO + H2O → K2 [Cu (OH)4]
Cupric oxide reacts with hydrogen and gets reduced to copper.
CuO + H2 → Cu + H2O
Cupric oxide reacts with carbon monoxide and forms elemental copper and carbon dioxide.
CuO + CO → Cu + CO2
Cupric oxide reacts with carbon and forms the elemental form of copper.
2CuO + C → 2Cu + CO2
Uses of Cupric Oxide
Cupric oxide is used as a pigmenting agent in ceramic compounds. It gives blue, red, green, grey, pink, and black glazes.
Cupric oxide is widely used in laboratories for the preparation of various copper salts.
Cupric oxide is used in the manufacture of wood preservatives.
Cupric oxide is used in the welding process.
Cupric oxide is used in the manufacture of lithium batteries.
Did You Know?
Paramelaconite is a copper mineral. In this mineral, copper exists in both +1 and +2 oxidation state.
Do you think that copper was the first element used by man along with gold and iron?
Copper is an essential element for the human body.
Copper is used in alloy formation.
The blood of octopus contains copper as an oxygen carrier. Therefore, the colour of the blood in them is blue.
Copper is an essential trace mineral.
Copper is used as a supplement with iron for the anaemic person.
FAQs on Cupric Oxide CuO Structure Properties and Applications
1. What is cupric oxide?
Cupric oxide is copper(II) oxide, a black solid compound with the chemical formula CuO. It contains copper in the +2 oxidation state combined with oxygen.
Key facts about cupric oxide:
- Chemical formula: CuO
- Appearance: Black crystalline solid
- Type: Metal oxide and basic oxide
- Common name: Cupric oxide
2. What is the chemical formula and molar mass of cupric oxide?
The chemical formula of cupric oxide is CuO, and its molar mass is approximately 79.55 g/mol.
Molar mass calculation:
- Atomic mass of Cu ≈ 63.55 g/mol
- Atomic mass of O ≈ 16.00 g/mol
- Total = 63.55 + 16.00 = 79.55 g/mol
3. How is cupric oxide prepared in the laboratory?
Cupric oxide is commonly prepared by heating copper in oxygen or by decomposing copper(II) salts.
Common laboratory methods:
- By heating copper metal in air:
2Cu(s) + O2(g) → 2CuO(s) - By thermal decomposition of copper(II) carbonate:
CuCO3(s) → CuO(s) + CO2(g)
4. Is cupric oxide acidic or basic?
Cupric oxide (CuO) is a basic oxide because it reacts with acids to form salt and water.
Example reaction with hydrochloric acid:
CuO(s) + 2HCl(aq) → CuCl2(aq) + H2O(l)
Key points:
- It does not react with bases under normal conditions.
- It forms copper(II) salts when treated with acids.
5. What is the difference between cupric oxide and cuprous oxide?
The main difference is that cupric oxide is CuO (copper in +2 state), while cuprous oxide is Cu2O (copper in +1 state).
Comparison:
- CuO: Black solid, copper(II) oxide, Cu2+
- Cu2O: Reddish-brown solid, copper(I) oxide, Cu+
6. How does cupric oxide react with hydrogen?
Cupric oxide is reduced by hydrogen to form copper metal and water.
The balanced reduction reaction is:
CuO(s) + H2(g) → Cu(s) + H2O(g)
Key points:
- CuO acts as the oxidizing agent.
- Hydrogen acts as the reducing agent.
- This is a redox reaction commonly demonstrated in laboratories.
7. What happens when cupric oxide reacts with sulfuric acid?
When cupric oxide reacts with sulfuric acid, it forms copper(II) sulfate and water.
The balanced equation is:
CuO(s) + H2SO4(aq) → CuSO4(aq) + H2O(l)
Important points:
- This is a neutralization reaction.
- CuO behaves as a basic oxide.
- Blue copper(II) sulfate solution is formed.
8. What are the common uses of cupric oxide?
Cupric oxide (CuO) is used in ceramics, catalysts, batteries, and as a pigment.
Main applications include:
- Black pigment in ceramics and glass
- Catalyst in chemical reactions
- Component in dry cell batteries
- Precursor for preparing copper salts
9. Is cupric oxide soluble in water?
Cupric oxide (CuO) is insoluble in water but soluble in acids.
Solubility behavior:
- In water: No significant dissolution
- In acids: Dissolves to form copper(II) salts
CuO(s) + 2HNO3(aq) → Cu(NO3)2(aq) + H2O(l)
This property is typical of many basic metal oxides.
10. What is the oxidation state of copper in cupric oxide?
The oxidation state of copper in cupric oxide (CuO) is +2.
Explanation:
- Oxygen usually has an oxidation state of −2.
- Since CuO is electrically neutral, copper must be +2 to balance −2 from oxygen.
