Assertion : `RCOCl` is reduced to `RCHO` with `H_(2)` using `Pd//BaSO_(4)` catalyst contaning a small amount of sulphur.
Reason : RCHO is further reduced to `RCH_(2)OH`.

Options

A. If both assertion and reason are correct and reason is correct explanation for assertion.
B. If both assertion and reason are correct and reason is not correct explanation for assertion.
C. If assertion is correct but reason is incorrect.
D. If assertion as well as reason are both incorrect.

Explanation

To solve the given question, we will analyze both the assertion and the reason step by step.

### Step 1: Understanding the Assertion
The assertion states that `RCOCl` (an acid chloride) is reduced to `RCHO` (an aldehyde) using `H2` with a catalyst of `Pd/BaSO4` that contains a small amount of sulfur.

- **Explanation**: This process is known as the Rosenmund reduction. In this reaction, acid chlorides are converted to aldehydes by treating them with hydrogen gas in the presence of a palladium catalyst supported on barium sulfate (BaSO4). The small amount of sulfur acts as a poison to the catalyst, which prevents further reduction of the aldehyde to an alcohol.

**Hint**: Recall the Rosenmund reduction mechanism and the role of sulfur in preventing over-reduction.

### Step 2: Understanding the Reason
The reason states that `RCHO` (the aldehyde) is further reduced to `RCH2OH` (an alcohol).

- **Explanation**: This statement is incorrect in the context of the assertion. The presence of sulfur in the catalyst prevents the aldehyde from being further reduced to the alcohol. Therefore, while aldehydes can be reduced to alcohols under different conditions, in this specific reaction setup, the aldehyde does not undergo further reduction.

**Hint**: Consider the effects of catalyst poisoning and how it influences the reaction pathway.

### Step 3: Conclusion
Based on the analysis:
- The assertion is correct: `RCOCl` is indeed reduced to `RCHO` using `H2` with a Pd/BaSO4 catalyst containing sulfur.
- The reason is incorrect: `RCHO` is not further reduced to `RCH2OH` in this reaction setup due to the presence of sulfur.

Thus, the final conclusion is:
- **Assertion is correct, but the reason is incorrect.**

### Final Answer:
The correct answer is option 3: Assertion is correct but the reason is incorrect.