A substance which participates readily in both acid-base and oxidation-reduction reactions is:

Options

A. `Na_(2) CO_(3)`
B. KOH
C. `KMnO_(4)`
D. `H_(2)C_(2)O_(4)`

Answer

To solve the question, we need to identify a substance that readily participates in both acid-base reactions and oxidation-reduction reactions. Let's analyze the options step by step.

### Step 1: Analyze the Options
We have the following substances to consider:
1. Sodium Carbonate (Na2CO3)
2. KMnO4 (Potassium Permanganate)
3. Oxalic Acid (H2C2O4)

### Step 2: Evaluate Sodium Carbonate (Na2CO3)
- Sodium carbonate is primarily a basic substance.
- It can react with acids to form salts and water, thus participating in acid-base reactions.
- However, it does not participate in oxidation-reduction reactions because it does not have variable oxidation states.

**Conclusion**: Na2CO3 does not meet the criteria.

### Step 3: Evaluate KMnO4 (Potassium Permanganate)
- KMnO4 contains manganese, which can exist in multiple oxidation states (from +2 to +7).
- It acts as a strong oxidizing agent in reactions, thus readily participating in oxidation-reduction reactions.
- However, KMnO4 does not participate in acid-base reactions as it does not donate or accept protons (H+ ions).

**Conclusion**: KMnO4 does not meet the criteria.

### Step 4: Evaluate Oxalic Acid (H2C2O4)
- Oxalic acid is a weak organic acid that can donate protons (H+) and thus participates in acid-base reactions.
- It can also undergo oxidation-reduction reactions. For example, when it reacts with KMnO4, the oxidation state of carbon in oxalic acid changes, indicating that it can act as a reducing agent.
- The presence of ionizable hydrogens allows it to participate in acid-base reactions, while the ability to change oxidation states allows it to participate in redox reactions.

**Conclusion**: H2C2O4 meets both criteria.

### Final Answer
The substance that participates readily in both acid-base and oxidation-reduction reactions is **H2C2O4 (Oxalic Acid)**.

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