`H-C-=C-H underset(H_(2)SO_(4))overset(HgSO_(4))rarr(A)underset((2)H_(3)O^(o+))overset((1)NH_(3)+HCN)rarr(B)`, Product (B) of given reaction is :

Options

A. Glycine
B. Alanine
C. valine
D. Leucine

Explanation

To solve the problem step by step, we will analyze the given reactions and identify the product (B) formed from the starting material.

### Step 1: Identify the starting material
The starting material is H-C≡C-H, which is ethyne (acetylene).

### Step 2: First Reaction with H₂SO₄ and HgSO₄
When ethyne is treated with sulfuric acid (H₂SO₄) in the presence of mercury(II) sulfate (HgSO₄), it undergoes hydration to form an intermediate enol, which then tautomerizes to form a ketone. The reaction can be summarized as follows:
- Ethyne reacts with H₂SO₄ and HgSO₄ to form acetaldehyde (CH₃CHO).

### Step 3: Hydrolysis
The product from the first step (acetaldehyde) can undergo hydrolysis. However, in this case, the hydrolysis is not necessary as we already have the aldehyde.

### Step 4: Reaction with NH₃ and HCN
Next, acetaldehyde reacts with ammonia (NH₃) and hydrogen cyanide (HCN). This reaction leads to the formation of a cyanohydrin. The cyanohydrin will have the following structure:
- The carbonyl carbon of acetaldehyde will bond with NH₂ from ammonia and CN from HCN, resulting in the formation of a compound with an amino group (NH₂) and a cyano group (CN).

### Step 5: Final Product Formation
Upon hydrolysis of the cyanohydrin, the cyano group (CN) will be converted into a carboxylic acid (COOH). The final product will have the structure:
- CH₃-CH(NH₂)-COOH, which is the structure of alanine.

### Conclusion
Thus, the product (B) of the given reaction is alanine.

### Final Answer
Product (B) is alanine.

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