Which of the following reactions cannot occur ?

Options

A. `2AgNO_(3(aq)) + Fe_((s)) to Fe(NO_(3))_(2(Aq)) + 2Ag_((s))`
B. `CuSO_(4(aq)) + Zn_((s)) to ZnSO_(4(aq)) + Cu_((s))`
C. `CuSO_(4(aq)) + 2Ag_((s)) to Cu_((s)) +Ag_(2)SO_(4(aq))`
D. `2AgNO_(3(aq)) + Zn_((s)) to Zn(NO_(3))_(2(aq)) + 2Ag_((s))`

Explanation

To determine which of the following reactions cannot occur, we need to analyze the reactivity of the metals involved in each reaction. The metals mentioned are silver (Ag), iron (Fe), copper (Cu), and zinc (Zn).

### Step-by-Step Solution:

1. **Identify the Reactivity Order of Metals**:
- The reactivity order for the metals in question is:
- Zinc (Zn) > Iron (Fe) > Copper (Cu) > Silver (Ag)
- This means zinc is the most reactive, followed by iron, then copper, and silver is the least reactive.

2. **Analyze Each Reaction**:
- **Reaction A**: Iron (Fe) + Silver Nitrate (AgNO3) → ?
- Iron can displace silver because it is more reactive than silver. This reaction can occur.
- **Reaction B**: Zinc (Zn) + Copper Sulphate (CuSO4) → ?
- Zinc can displace copper because it is more reactive than copper. This reaction can occur.
- **Reaction C**: Silver (Ag) + Copper Sulphate (CuSO4) → ?
- Silver cannot displace copper because it is less reactive than copper. This reaction cannot occur.
- **Reaction D**: Zinc (Zn) + Silver Nitrate (AgNO3) → ?
- Zinc can displace silver because it is more reactive than silver. This reaction can occur.

3. **Conclusion**:
- The only reaction that cannot occur is **Reaction C**, where silver attempts to displace copper from copper sulphate.

### Final Answer:
The reaction that cannot occur is **Reaction C**: Silver (Ag) + Copper Sulphate (CuSO4).