Reduction potentials of A, B, C and D are 0.8 V, 0.79 V, 0.34 V and respectively. Which element displaces all the other three elements?

Options

A. A
B. B
C. D
D. C

Explanation

To determine which element can displace all the other three elements (A, B, and C), we need to analyze their reduction potentials. The element with the lowest reduction potential will be the strongest reducing agent and will be able to displace the others.

### Step-by-Step Solution:

1. **List the Reduction Potentials**:
- A: 0.8 V
- B: 0.79 V
- C: 0.34 V
- D: -2.37 V

2. **Identify the Strongest Reducing Agent**:
- The strongest reducing agent corresponds to the lowest reduction potential. In this case, D has the lowest reduction potential at -2.37 V.

3. **Understand Displacement**:
- An element can displace another if it can reduce it. This is possible if the reducing agent (the one doing the displacing) has a lower (more negative) reduction potential than the element being displaced.

4. **Comparison of Reduction Potentials**:
- Since D has the lowest reduction potential (-2.37 V), it can reduce A, B, and C, which have higher reduction potentials (0.8 V, 0.79 V, and 0.34 V respectively).

5. **Conclusion**:
- Therefore, element D can displace all the other three elements (A, B, and C).

### Final Answer:
Element D displaces all the other three elements (A, B, and C).

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