A: `H_(2) and O_(2)` are obtained if dil. Solution of `Na_(2)SO_(4)` is electrolysed using Pt electrodes.
R: Platinum electrode is inert electrode.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1)
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2)
C. If Assertion is true statement but Reason is false, then mark (3)
D. If both Assertion and Reason are false statements then mark (4)

Answer

To solve the question, we need to analyze the assertion and reason provided.

### Step-by-Step Solution:

1. **Understanding the Electrolysis of Na2SO4**:
- When a dilute solution of sodium sulfate (Na2SO4) is electrolyzed, the solution contains Na⁺, SO₄²⁻, H₂O, and the ions from water (H⁺ and OH⁻).
- The presence of water is significant because it is the main solvent and will participate in the electrolysis process.

2. **Identifying the Electrodes**:
- The electrodes used are platinum (Pt) electrodes, which are known to be inert. This means they do not participate in the chemical reactions occurring during electrolysis.

3. **Electrolysis Process**:
- At the **cathode** (negative electrode), reduction occurs. The H⁺ ions from water will gain electrons to form hydrogen gas (H₂).
\[ 2H^+ + 2e^- \rightarrow H_2(g) \]
- At the **anode** (positive electrode), oxidation occurs. The OH⁻ ions from water will lose electrons to produce oxygen gas (O₂).
\[ 4OH^- \rightarrow 2H_2O + O_2(g) + 4e^- \]

4. **Products of Electrolysis**:
- Therefore, the products of the electrolysis of dilute Na2SO4 are hydrogen gas (H₂) at the cathode and oxygen gas (O₂) at the anode.

5. **Evaluating the Assertion and Reason**:
- **Assertion (A)**: "H₂ and O₂ are obtained if dilute solution of Na₂SO₄ is electrolyzed using Pt electrodes." - This statement is true.
- **Reason (R)**: "Platinum electrode is an inert electrode." - This statement is also true.
- However, while both statements are correct, the reason does not directly explain the assertion. The inert nature of platinum does not influence the production of H₂ and O₂; it simply means that platinum does not participate in the reaction.

### Conclusion:
Both the assertion and reason are correct, but they are not related to each other. Therefore, the correct answer is that both statements are true, but the reason does not explain the assertion.