Assertion: `SO_(2)` gas is easily liquefied while `H_(2)` is not.
Reason: `SO_(2)` has low critical temperature while`H_(2)` has high critical temperature.

Options

A. If both (`A`) and (`R`) are correct and (`R`) is the correct explanation of (`A`).
B. If both (`A`) and (`R`) are correct, but (`R`) is not the correct explanation of (`A`).
C. If (`A`) is correct, but (`R`) is incorrect.
D. If (`A`) is incorrect, but (`R`) is correct.

Explanation

To solve the question, we need to analyze the assertion and reason provided regarding the liquefaction of gases SO₂ and H₂, as well as their critical temperatures.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that SO₂ gas is easily liquefied while H₂ is not. This is true because SO₂ has stronger intermolecular forces compared to H₂, which is a diatomic molecule with very weak van der Waals forces.

2. **Understanding the Reason**:
- The reason given is that SO₂ has a low critical temperature while H₂ has a high critical temperature. This statement is incorrect. In fact, for a gas to be easily liquefied, it should have a **high** critical temperature, not a low one. The critical temperature is the temperature above which a gas cannot be liquefied, regardless of the pressure applied.

3. **Critical Temperature and Van der Waals Constant**:
- The critical temperature (T_c) is related to the Van der Waals constant (A) by the formula:
\[ T_c = \frac{8A}{27Rb} \]
- Here, R is the universal gas constant and b is the volume excluded per mole of the gas. A higher value of A indicates stronger intermolecular forces, which in turn leads to a higher critical temperature.

4. **Comparison of SO₂ and H₂**:
- Since SO₂ has a higher value of A compared to H₂, it implies that SO₂ has stronger attractive forces between its molecules, leading to a higher critical temperature. Therefore, SO₂ is more easily liquefied than H₂.

5. **Conclusion**:
- The assertion is true: SO₂ is easily liquefied while H₂ is not.
- The reason is false: SO₂ has a **high** critical temperature, not a low one, and H₂ has a **low** critical temperature.
- Therefore, the correct answer is that the assertion is correct but the reason is incorrect.

### Final Answer:
- Assertion: True
- Reason: False
- Correct option: A is correct but the reason is incorrect.