Copper is very slowly oxidised on the surface in moist air, giving a green coating of vergiris is :

Options

A. `Cu_(2)O`
B. `CuCO_(3)`
C. `Cu(CH_(3)COO)_(2)*Cu(OH)_(2)`
D. `CuSO_(4)`

Answer

To solve the question regarding the oxidation of copper in moist air and the formation of a green coating known as verdigris, we can break down the process step by step.

### Step-by-Step Solution:

1. **Understanding the Environment**:
- Copper is exposed to moist air, which contains both carbon dioxide (CO2) and oxygen (O2).

2. **Oxidation Reaction**:
- In the presence of moisture and air, copper undergoes a slow oxidation process. The general reaction can be represented as:
\[ \text{Cu} + \text{O}_2 + \text{H}_2\text{O} \rightarrow \text{Cu(OH)}_2 \]
- Here, copper reacts with oxygen and water to form copper(II) hydroxide.

3. **Formation of Carbonate**:
- The copper(II) hydroxide can further react with carbon dioxide in the air to form copper(II) carbonate:
\[ \text{Cu(OH)}_2 + \text{CO}_2 \rightarrow \text{CuCO}_3 + \text{H}_2\text{O} \]

4. **Reaction with Acetic Acid**:
- When copper(II) carbonate reacts with acetic acid (CH3COOH), it forms a complex that gives the characteristic green color of verdigris:
\[ \text{CuCO}_3 + 2\text{CH}_3\text{COOH} \rightarrow \text{Cu(CH}_3\text{COO})_2 + \text{H}_2\text{O} + \text{CO}_2 \]

5. **Conclusion**:
- The green coating observed on copper is indeed verdigris, which is primarily composed of copper(II) acetate and other copper compounds formed through these reactions.

### Final Answer:
The green coating of verdigris on copper is formed as a result of its slow oxidation in moist air, leading to the formation of copper(II) hydroxide and subsequently copper(II) carbonate, which reacts with acetic acid.