Hydration of acetylene in the presence of dilute sulphuric acid and `Hg^(2+)` ions at `80^(@)`C gives :

Options

A. Ethanol
B. Ethanal
C. Vinyl alcohol
D. All of these

Answer

To solve the question regarding the hydration of acetylene in the presence of dilute sulfuric acid and `Hg^(2+)` ions at `80°C`, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**: The reactants are acetylene (C₂H₂), dilute sulfuric acid (H₂SO₄), and mercuric ions (Hg²⁺).

2. **Understanding the Reaction Conditions**: The reaction occurs at a temperature of `80°C`. Under these conditions, acetylene can undergo hydration.

3. **Formation of a Complex**: When acetylene reacts with dilute sulfuric acid and Hg²⁺ ions, a mercuric ion complex is formed with the triple bond of acetylene. This complex facilitates the addition of water.

4. **Addition of Water**: A water molecule is added to the complex. The triple bond in acetylene opens up, allowing the addition of the hydroxyl group (OH) from water and a hydrogen atom (H) from the acid.

5. **Formation of Enol**: The product formed after the addition of water is an enol, specifically vinyl alcohol (CH₂=CHOH). This is an unstable intermediate.

6. **Tautomerization**: The enol (vinyl alcohol) undergoes tautomerization to form a more stable keto form. In this case, vinyl alcohol converts to acetaldehyde (CH₃CHO).

7. **Final Product**: The final product of the reaction is acetaldehyde (CH₃CHO).

### Final Answer:
The hydration of acetylene in the presence of dilute sulfuric acid and `Hg^(2+)` ions at `80°C` gives **acetaldehyde (CH₃CHO)**.