Which of the following set of reactions will Not occur ?
(I) `MgSO_(4)(aq)+Fe(s)toFeSO_(4)(aq)+Mg(s)`
(II) `CuSO_(4)(aq)+Fe(s)toFeSO_(4)(aq)+Cu(s)`
(III) `MgSO_(4)(aq)+Cu(s)toCuSO_(4)(aq)+Mg(s)`
(IV) `CuSO_(4)(aq)+Zn(s)toZnSO_(4)(aq)+CU(s)`

Options

A. I and III
B. II and IV
C. I,II and III
D. II,III and IV

Explanation

To determine which of the following reactions will not occur, we need to analyze each reaction based on the reactivity series of metals. The reactivity series ranks metals from most reactive to least reactive, and a more reactive metal can displace a less reactive metal from its compound.

### Step-by-step Solution:

1. **Analyze Reaction I:**
\[ \text{MgSO}_4(aq) + \text{Fe}(s) \to \text{FeSO}_4(aq) + \text{Mg}(s) \]
- In this reaction, magnesium (Mg) is more reactive than iron (Fe).
- Since magnesium cannot be displaced by iron, this reaction will **not occur**.

2. **Analyze Reaction II:**
\[ \text{CuSO}_4(aq) + \text{Fe}(s) \to \text{FeSO}_4(aq) + \text{Cu}(s) \]
- Here, iron (Fe) is more reactive than copper (Cu).
- Iron can displace copper from copper sulfate, so this reaction **will occur**.

3. **Analyze Reaction III:**
\[ \text{MgSO}_4(aq) + \text{Cu}(s) \to \text{CuSO}_4(aq) + \text{Mg}(s) \]
- In this case, magnesium (Mg) is more reactive than copper (Cu).
- Copper cannot displace magnesium from magnesium sulfate, so this reaction will **not occur**.

4. **Analyze Reaction IV:**
\[ \text{CuSO}_4(aq) + \text{Zn}(s) \to \text{ZnSO}_4(aq) + \text{Cu}(s) \]
- Zinc (Zn) is more reactive than copper (Cu).
- Zinc can displace copper from copper sulfate, so this reaction **will occur**.

### Conclusion:
The reactions that will **not occur** are:
- Reaction I: \(\text{MgSO}_4(aq) + \text{Fe}(s) \to \text{FeSO}_4(aq) + \text{Mg}(s)\)
- Reaction III: \(\text{MgSO}_4(aq) + \text{Cu}(s) \to \text{CuSO}_4(aq) + \text{Mg}(s)\)

Thus, the answer is that reactions I and III will not occur.