The compound that can work both as an oxidising as well as reducing agent is :

Options

A. `KMnO_(4)`
B. `H_(2)O_(2)`
C. `Fe_(2)(SO_(4))_(3)`
D. `K_(2)Cr_(2)O_(7)`

Answer

To determine the compound that can act both as an oxidizing agent and a reducing agent, we need to analyze the oxidation states of the elements in the given compounds.

### Step-by-Step Solution:

1. **Understanding Oxidizing and Reducing Agents**:
- An **oxidizing agent** is a substance that gains electrons (is reduced) and, in doing so, causes another substance to be oxidized (lose electrons).
- A **reducing agent** is a substance that loses electrons (is oxidized) and, in doing so, causes another substance to be reduced (gain electrons).

2. **Identifying the Compounds**:
- The question mentions several compounds, including KMnO4, H2O2, Fe2(SO4)3, and K2Cr2O7.

3. **Analyzing KMnO4**:
- In KMnO4, manganese (Mn) has an oxidation state of +7. It can only act as an oxidizing agent because it can only be reduced (decrease in oxidation state).

4. **Analyzing H2O2**:
- In H2O2, the oxidation state of oxygen is -1. Oxygen can be oxidized to 0 (losing electrons) or reduced to -2 (gaining electrons). Therefore, H2O2 can act as both an oxidizing agent and a reducing agent.

5. **Analyzing Fe2(SO4)3**:
- In Fe2(SO4)3, iron (Fe) has an oxidation state of +3. It can be reduced to +2, thus acting as an oxidizing agent. However, it cannot act as a reducing agent since it cannot increase its oxidation state beyond +3.

6. **Analyzing K2Cr2O7**:
- In K2Cr2O7, chromium (Cr) has an oxidation state of +6. It can only act as an oxidizing agent because it can be reduced but cannot act as a reducing agent.

7. **Conclusion**:
- Among the compounds analyzed, only H2O2 can act both as an oxidizing agent and a reducing agent due to the variable oxidation states of oxygen.

### Final Answer:
The compound that can work both as an oxidizing as well as a reducing agent is **H2O2 (Hydrogen Peroxide)**.