In the following reaction
`C_(2)H_(2)underset(HgSO_(4)//H_(2)SO_(4),60^(@)C)overset(H_(2)O)toXhArrCH_(3)CHO`
What is X?

Options

A. `CH_(3)CH_(2)OH`
B. `CH_(2)=CHOH`
C. `CH_(3)CH_(2)CHO`
D. `CH_(3)-O-CH_(3)`

Answer

To solve the question, we need to analyze the reaction step by step:

### Step 1: Identify the Reactants
The reactant given is ethyne (C₂H₂), also known as acetylene. The reaction occurs in the presence of water (H₂O) and a catalyst, which includes mercury(II) sulfate (HgSO₄) and sulfuric acid (H₂SO₄).

### Step 2: Understand the Reaction Mechanism
In the presence of water and the catalyst, ethyne undergoes hydration. This means that water will add across the triple bond of ethyne.

### Step 3: Addition of Water
When water adds to ethyne, the hydrogen (H) from water will attach to one carbon atom of the triple bond, and the hydroxyl group (OH) will attach to the other carbon atom. The structure of ethyne (C₂H₂) is:

```
H
|
H-C≡C-H
```

After the addition of water, we get:
```
H
|
H-C=CH-OH
```
This compound is known as vinyl alcohol (CH₂=CHOH).

### Step 4: Identify X
The compound formed after the hydration of ethyne is vinyl alcohol (CH₂=CHOH). Thus, we can conclude that X is vinyl alcohol.

### Step 5: Tautomerization
Vinyl alcohol (CH₂=CHOH) can undergo tautomerization, which is a rearrangement of the molecule to form a more stable compound. In this case, vinyl alcohol rearranges to form acetaldehyde (CH₃CHO).

### Final Answer
Therefore, the compound X that is formed in the reaction is vinyl alcohol (CH₂=CHOH).

### Summary
- **X = Vinyl Alcohol (CH₂=CHOH)**

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