For the given cell, `Mg | Mg^(2+) || Cu^(2+) | Cu`
1) Mg is cathode
2) Cu is cathode
3) The cell reaction is `Mg + Cu^(2+) to Mg^(2+) + Cu`
4) Cu is the oxidising agent.

Options

A. 1 & 3
B. 1 & 4
C. 2 & 3
D. 2 & 4

Answer

To solve the problem regarding the electrochemical cell represented as `Mg | Mg^(2+) || Cu^(2+) | Cu`, we will analyze the oxidation and reduction processes occurring in the cell and determine the correct statements from the given options.

### Step-by-Step Solution:

1. **Identify Oxidation and Reduction:**
- In the cell representation, magnesium (Mg) is in the elemental form (0 oxidation state) and is being oxidized to magnesium ions (Mg^(2+), +2 oxidation state).
- Copper ions (Cu^(2+), +2 oxidation state) are being reduced to elemental copper (Cu, 0 oxidation state).

2. **Determine Anode and Cathode:**
- The anode is where oxidation occurs. Since Mg is oxidized to Mg^(2+), Mg is the anode.
- The cathode is where reduction occurs. Since Cu^(2+) is reduced to Cu, Cu is the cathode.

3. **Write Half-Reactions:**
- Anodic reaction (oxidation):
\[ \text{Mg} \rightarrow \text{Mg}^{2+} + 2e^- \]
- Cathodic reaction (reduction):
\[ \text{Cu}^{2+} + 2e^- \rightarrow \text{Cu} \]

4. **Overall Cell Reaction:**
- The overall cell reaction can be obtained by combining the half-reactions:
\[ \text{Mg} + \text{Cu}^{2+} \rightarrow \text{Mg}^{2+} + \text{Cu} \]

5. **Identify Oxidizing and Reducing Agents:**
- The oxidizing agent is the species that gets reduced. Here, Cu^(2+) is reduced to Cu, so Cu^(2+) acts as the oxidizing agent.
- Conversely, Mg is oxidized, making it the reducing agent.

6. **Evaluate the Given Statements:**
- **Statement 1:** Mg is cathode. (False, Mg is anode)
- **Statement 2:** Cu is cathode. (True, Cu is cathode)
- **Statement 3:** The cell reaction is Mg + Cu^(2+) to Mg^(2+) + Cu. (True, this is the overall reaction)
- **Statement 4:** Cu is the oxidizing agent. (False, Cu is reduced; Cu^(2+) is the oxidizing agent)

### Conclusion:
The correct statements are:
- **Option 2:** Cu is cathode (True).
- **Option 3:** The cell reaction is Mg + Cu^(2+) to Mg^(2+) + Cu (True).

### Final Answer:
The correct options are 2 and 3.

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