When copper is exposed to moist air containing carbon dioxide, it reacts to form a complex mixture of copper carbonates and hydroxides, often referred to as patina. The simplified reaction involves copper reacting with oxygen, water, and carbon dioxide to form basic copper carbonate, typically Cu₂(OH)₂CO₃ (malachite), which has a characteristic green colour.
On exposure to moist air, copper gains a green coat on its surface due to formation of which one of the following compounds ?
Asked in UPSC NDA 1 2019 · Topic: Metals, Minerals, Ores: Properties, Uses (Corrosion of metals: causes, mechanism (rusting), and prevention methods (galvanization, anodizing, electroplating, alloying, painting))
More Chemistry questions
- Zinc is used to protect iron from corrosion because zinc is
- To protect steel and iron from rusting, a thin layer of which one of the following metals is applied ?
- Silver artefacts get tarnished in air due to the formation of
- Galvanization is a method of protecting iron from rusting by coating with a thin layer of
- Which of the following is protected by passivation?
- With reference to ‘Silver articles’, which of the following statements is/are correct ? 1. Silver articles turn black after some time when exposed to air. 2. It happens due to coating of silver sulphide. Select the correct answer from the code given below : Code :
- Galvanisation is
- Iron is galvanized by