Which of the following solutions can be safely stored in a copper vessel ?
(a)`ZnSO_(4)`
(b)`AgNO_(3)`
(c)`AuCl_(3)`
(d)All of them.

Options

A. `ZnSO_(4)`
B. `AgNO_(3)`
C. `AuCl_(3)`
D. All of them.

Explanation

To determine which of the given solutions can be safely stored in a copper vessel, we need to analyze the reactivity of copper in relation to the other metals present in the solutions.

### Step-by-step Solution:

1. **Understanding Reactivity Series**:
- The reactivity series is a list of metals arranged in order of decreasing reactivity. In this series, metals that are more reactive can displace those that are less reactive from their compounds.

2. **Analyzing Zinc Sulfate (`ZnSO4`)**:
- Copper (Cu) is less reactive than zinc (Zn). Therefore, when copper is placed in a zinc sulfate solution, it cannot displace zinc from the solution.
- **Conclusion**: Copper can be safely stored in zinc sulfate.

3. **Analyzing Silver Nitrate (`AgNO3`)**:
- Copper is more reactive than silver (Ag). If copper is placed in silver nitrate, it will displace silver from the solution, leading to a chemical reaction.
- The reaction can be represented as:
\[ 2AgNO_3 + Cu \rightarrow Cu(NO_3)_2 + 2Ag \]
- **Conclusion**: Copper cannot be safely stored in silver nitrate.

4. **Analyzing Gold Chloride (`AuCl3`)**:
- Similarly, copper is also more reactive than gold (Au). If copper is placed in gold chloride, it will displace gold from the solution, resulting in a chemical reaction.
- The reaction can be represented as:
\[ 3Cu + 2AuCl_3 \rightarrow 3CuCl_2 + 2Au \]
- **Conclusion**: Copper cannot be safely stored in gold chloride.

5. **Final Decision**:
- From the analysis, we find that copper can be safely stored in zinc sulfate but not in silver nitrate or gold chloride. Therefore, the only solution that can be safely stored in a copper vessel is:
- **Answer**: (a) `ZnSO4`.