Which of the following are the common oxidising agents used in redox titrations ?

Options

A. `K_(2)Cr_(2)O_(7), KMnO_(4)`, Iodine
B. `FeSO_(4), KMnO_(4)`, Sodium thiosulphate
C. Oxalic acid, `KMnO_(4), CuSO_(4)`
D. Mohr's salt, KI, Sodium sulphate

Explanation

To determine the common oxidizing agents used in redox titrations, we can analyze the common substances typically employed in these reactions. Here’s a step-by-step solution:

### Step 1: Identify Common Oxidizing Agents
In redox titrations, oxidizing agents are substances that gain electrons and are reduced in the process. Common oxidizing agents include:

1. **Potassium Permanganate (KMnO4)**
2. **Potassium Dichromate (K2Cr2O7)**
3. **Iodine (I2)**

### Step 2: Understand Their Oxidation States
- **KMnO4**: In this compound, manganese (Mn) is in the +7 oxidation state. During the titration, it can be reduced to MnO2 or Mn^2+, which are lower oxidation states.
- **K2Cr2O7**: Here, chromium (Cr) is in the +6 oxidation state. It can be reduced to Cr^3+ during the titration.
- **Iodine (I2)**: Iodine can be reduced to iodide ions (I^-), where it has an oxidation state of -1.

### Step 3: Conclusion
These substances are commonly used as oxidizing agents in redox titrations due to their ability to undergo reduction while oxidizing other substances.

### Final Answer
The common oxidizing agents used in redox titrations are:
- Potassium Permanganate (KMnO4)
- Potassium Dichromate (K2Cr2O7)
- Iodine (I2)

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