A metal X displaces nickel from nickel sulphate solution but does not displace manganese from manganese sulphate solution. What is the correct order of their reducing powers ?

Options

A. `Ni gt Mn gt X`
B. `X gt Mn gt Ni`
C. `Mn gt X gt Ni`
D. `Mn gt Ni gt X`

Explanation

To determine the correct order of reducing powers of the metals X, nickel, and manganese based on the information provided, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Displacement Reaction**:
- Metal X displaces nickel from nickel sulfate solution. This indicates that X is more reactive than nickel. In terms of reducing power, this means that X has a higher reducing power than nickel.
- Metal X does not displace manganese from manganese sulfate solution. This indicates that manganese is more reactive than X. Therefore, manganese has a higher reducing power than X.

2. **Establishing Reactivity Order**:
- From the above observations, we can establish the following reactivity order:
- X > Nickel (since X displaces nickel)
- Manganese > X (since X does not displace manganese)
- Combining these two relationships gives us the overall order of reactivity:
- Manganese > X > Nickel

3. **Relating Reactivity to Reducing Power**:
- Reducing power is inversely proportional to the standard reduction potential (E°). This means that a more reactive metal (which has a lower E° value) will have a higher reducing power.
- Since we have established the reactivity order as Manganese > X > Nickel, we can deduce the order of reducing powers as:
- Reducing Power: Manganese > X > Nickel

4. **Final Conclusion**:
- Therefore, the correct order of reducing powers is:
- Manganese > X > Nickel