The life of a daniel cell may be increased by:

Options

A. Maintaining low temperature
B. Using a large copper electrode
C. Decreasing the concentration of copper ions
D. Using large zinc electrodes

Answer

To solve the question about how to increase the life of a Daniel cell, we need to analyze the options provided and understand the workings of the Daniel cell.

### Step-by-Step Solution:

1. **Understand the Daniel Cell**:
- A Daniel cell is an electrochemical cell that converts chemical energy into electrical energy. It consists of two electrodes: a zinc electrode (anode) and a copper electrode (cathode), immersed in their respective sulfate solutions (zinc sulfate and copper sulfate).

2. **Identify the Reactions**:
- At the anode (zinc electrode), oxidation occurs:
\[ \text{Zn} \rightarrow \text{Zn}^{2+} + 2e^- \]
- At the cathode (copper electrode), reduction occurs:
\[ \text{Cu}^{2+} + 2e^- \rightarrow \text{Cu} \]

3. **Analyze the Options**:
- **Option 1: Maintaining low temperature**: This does not significantly affect the life of the Daniel cell.
- **Option 2: Using a large copper electrode**: The size of the copper electrode does not impact the lifespan since copper ions are reduced and deposited on the electrode.
- **Option 3: Decreasing the concentration of copper ions**: This would not help increase the lifespan of the cell as it would limit the reduction process.
- **Option 4: Using large zinc electrodes**: This is the correct option. A larger zinc electrode allows more zinc to oxidize, which increases the lifespan of the cell.

4. **Conclusion**:
- The life of a Daniel cell can be increased by using large zinc electrodes, as this allows for more oxidation of zinc to occur, prolonging the cell's operation.

### Final Answer:
The life of a Daniel cell may be increased by **using large zinc electrodes**.

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