Action of acetylene on dilute `H_(2)SO_(4)` gives

Options

A. acetic acid
B. acetaldehyde
C. acetone
D. acetoacetic ester .

Explanation

To solve the question about the action of acetylene on dilute H₂SO₄, we can break down the process step by step:

### Step 1: Understand the Reactants
Acetylene (C₂H₂) is a simple alkyne with a triple bond between the two carbon atoms. When it reacts with dilute sulfuric acid (H₂SO₄), the reaction typically requires the presence of a catalyst, which in this case is mercuric sulfate (HgSO₄).

**Hint:** Identify the reactants and any catalysts involved in the reaction.

### Step 2: Reaction Mechanism
When acetylene reacts with dilute H₂SO₄ in the presence of HgSO₄, the reaction proceeds through an electrophilic addition mechanism. The sulfuric acid donates a proton (H⁺) to one of the carbon atoms in the triple bond, leading to the formation of a carbocation.

**Hint:** Recall the mechanism of electrophilic addition reactions and the role of the catalyst.

### Step 3: Markovnikov's Rule
According to Markovnikov's rule, when HX (where X is a halogen or in this case, an OH group from water) adds to an alkene or alkyne, the hydrogen atom will attach to the carbon with the most hydrogen atoms already. Therefore, the addition of water (H₂O) to the carbocation will lead to the formation of vinyl alcohol (ethenol).

**Hint:** Remember Markovnikov's rule for predicting the product of addition reactions.

### Step 4: Tautomerization
Vinyl alcohol (C₂H₄O) is unstable and undergoes tautomerization to form acetaldehyde (C₂H₄O). During tautomerization, the hydroxyl group (OH) shifts to form a carbonyl group (C=O), resulting in the stable product acetaldehyde.

**Hint:** Understand the concept of tautomerization and how it converts one isomer into another.

### Step 5: Identify the Final Product
After the reaction and tautomerization, the final product formed from the action of acetylene on dilute H₂SO₄ is acetaldehyde (CH₃CHO).

**Hint:** Confirm the structure of the final product to ensure it matches the expected outcome.

### Conclusion
The action of acetylene on dilute H₂SO₄ gives acetaldehyde as the final product.

**Final Answer:** Acetaldehyde