Which of the following statements is/are correct regarding catalytic hydrogenation?

Options

A. It is an exothermic reaction
B. It is syn addition
C. Reactive intemediate is carbocation
D. Reactive intermediate is free radical.

Answer

To determine which statements are correct regarding catalytic hydrogenation, let's analyze each statement step by step.

### Step 1: Understand Catalytic Hydrogenation
Catalytic hydrogenation is a chemical reaction where hydrogen is added to an unsaturated compound (like an alkene) in the presence of a catalyst (commonly nickel, palladium, or platinum). This process converts alkenes into alkanes.

### Step 2: Analyze the Statements
1. **It is an exothermic reaction.**
- In catalytic hydrogenation, the reaction releases energy as the alkene (higher energy) is converted to an alkane (lower energy). Therefore, this statement is **correct**.

2. **It is a syn addition reaction.**
- During catalytic hydrogenation, both hydrogen atoms add to the same side of the double bond. This is known as syn addition. Thus, this statement is also **correct**.

3. **Intermediate is carbocation.**
- In catalytic hydrogenation, there is no formation of a carbocation intermediate. The reaction proceeds through the adsorption of the alkene and hydrogen on the catalyst surface, leading directly to the product without forming a carbocation. Therefore, this statement is **incorrect**.

4. **Reaction intermediate is free radical.**
- Similar to the previous point, there is no free radical intermediate formed in catalytic hydrogenation. The reaction proceeds without the generation of free radicals. Hence, this statement is also **incorrect**.

### Conclusion
Based on the analysis:
- The correct statements regarding catalytic hydrogenation are:
- It is an exothermic reaction.
- It is a syn addition reaction.

### Final Answer
The correct statements are:
1. It is an exothermic reaction.
2. It is a syn addition reaction.