In the following reacton, product P is
`R-overset(O)overset(||)C-Cloverset(H_(2))underset(Pd-BaSO_(4))rarrP`

Options

A. RCHO
B. `RCH_(3)`
C. RCOOH
D. `RCH_(2)OH`

Answer

To determine the product P in the given reaction, we need to analyze the reaction step by step.

### Step 1: Identify the starting material
The starting material in the reaction is an acid chloride, represented as R-C(=O)Cl. Acid chlorides are reactive compounds that can be converted into various functional groups.

**Hint:** Acid chlorides have the general structure R-C(=O)Cl, where R is an alkyl or aryl group.

### Step 2: Understand the reaction conditions
The reaction is carried out in the presence of H2 and Pd/BaSO4. This indicates that we are dealing with a Rosenmund reduction, which is a specific type of reduction that converts acid chlorides to aldehydes.

**Hint:** The presence of Pd/BaSO4 is crucial as it controls the extent of reduction, preventing further reduction to alcohol.

### Step 3: Apply the Rosenmund reduction mechanism
In the Rosenmund reduction, the acid chloride (R-C(=O)Cl) reacts with hydrogen (H2) in the presence of palladium on barium sulfate (Pd/BaSO4). The palladium acts as a catalyst, and the barium sulfate serves to limit the reaction, ensuring that the product is an aldehyde rather than a primary alcohol.

**Hint:** Remember that the Rosenmund reduction specifically converts acid chlorides to aldehydes without further reducing them to alcohols.

### Step 4: Determine the product
The product of the reaction is an aldehyde, which can be represented as R-C(=O)H. This product retains the same carbon skeleton as the starting acid chloride but has been converted to an aldehyde.

**Hint:** Aldehydes have the general structure R-C(=O)H, where R is the same as in the acid chloride.

### Conclusion
Thus, the product P in the reaction is an aldehyde, specifically R-C(=O)H.

**Final Answer:** The product P is R-C(=O)H (an aldehyde).