A student added a piece of zinc metal each to four different test tubes containing different solutions as given below. The test tube in which no reaction was observed, contains

Options

A. `Al_2(SO_4)_3`
B. `ZnSO_4`
C. `FeSO_4`
D. `CuSO_4`

Answer

To determine which test tube will show no reaction when zinc metal is added, we need to analyze the reactivity of zinc with the different solutions provided.

### Step-by-Step Solution:

1. **Identify the Reactivity of Zinc**:
Zinc (Zn) is a moderately reactive metal. It can displace less reactive metals from their salts but cannot displace more reactive metals.

2. **List the Solutions**:
The solutions mentioned are:
- Aluminum sulfate (Al2(SO4)3)
- Zinc sulfate (ZnSO4)
- Iron sulfate (FeSO4)
- Copper sulfate (CuSO4)

3. **Analyze Each Solution**:
- **Zinc with Aluminum Sulfate**:
- Zinc is less reactive than aluminum. Therefore, zinc cannot displace aluminum from aluminum sulfate.
- **No Reaction** will occur.

- **Zinc with Zinc Sulfate**:
- Zinc cannot displace itself from its own salt (zinc sulfate).
- **No Reaction** will occur.

- **Zinc with Iron Sulfate**:
- Zinc is more reactive than iron. Therefore, zinc can displace iron from iron sulfate.
- **Reaction** will occur, producing zinc sulfate and iron.

- **Zinc with Copper Sulfate**:
- Zinc is more reactive than copper. Therefore, zinc can displace copper from copper sulfate.
- **Reaction** will occur, producing zinc sulfate and copper.

4. **Conclusion**:
The test tubes in which no reaction is observed are those containing aluminum sulfate and zinc sulfate.

### Final Answer:
The test tube in which no reaction was observed contains **Aluminum sulfate (Al2(SO4)3)** or **Zinc sulfate (ZnSO4)**.