In the reaction `H-C-=CHoverset((1)NaNH_(2)//liq.NH_(3))underset((2)CH_(3)CH_(2)Br)rarr X, overset((i)NaNH_(2)//liq. NH_(3))underset((2)CH_(3)CH_(2)Br)rarr Y`
X and Y are :

Options

A. X = 1 - Butyne , Y = 3 - Hexyne
B. X = 2 - Butyne, Y = 3- Hexyne
C. X = 2 - Butyne , Y = 2- Hexyne
D. X = 1 - Butyne , Y = 2 - Hexyne

Answer

To solve the problem, we need to analyze the given reactions step by step.

### Step 1: Understanding the First Reaction
The first reaction is:
\[ \text{H-C} \equiv \text{C} \xrightarrow{\text{(1) NaNH}_2/\text{liq. NH}_3} \text{X} \xrightarrow{\text{(2) CH}_3\text{CH}_2\text{Br}} \]

1. **Deprotonation**: Sodium amide (NaNH₂) acts as a strong base and will deprotonate the terminal alkyne (1-butyne), resulting in the formation of a negative charge on the carbon atom.
\[ \text{H-C} \equiv \text{C} + \text{NaNH}_2 \rightarrow \text{C} \equiv \text{C}^- + \text{NH}_3 \]
The product is an acetylide ion (C≡C⁻).

2. **Nucleophilic Attack**: The acetylide ion will act as a nucleophile and attack the electrophilic carbon in ethyl bromide (CH₃CH₂Br).
\[ \text{C} \equiv \text{C}^- + \text{CH}_3\text{CH}_2\text{Br} \rightarrow \text{C} \equiv \text{C-CH}_2\text{CH}_3 + \text{Br}^- \]
The product X is 1-butyne (C₄H₆).

### Step 2: Understanding the Second Reaction
The second reaction is:
\[ \text{X} \xrightarrow{\text{(i) NaNH}_2/\text{liq. NH}_3} \text{Y} \xrightarrow{\text{(2) CH}_3\text{CH}_2\text{Br}} \]

1. **Deprotonation of X**: Again, sodium amide will deprotonate the terminal alkyne (now 1-butyne).
\[ \text{C} \equiv \text{C-CH}_2\text{CH}_3 + \text{NaNH}_2 \rightarrow \text{C} \equiv \text{C-CH}_2\text{CH}_3^- + \text{NH}_3 \]
This results in a new acetylide ion.

2. **Nucleophilic Attack**: The new acetylide ion will attack another molecule of ethyl bromide.
\[ \text{C} \equiv \text{C-CH}_2\text{CH}_3^- + \text{CH}_3\text{CH}_2\text{Br} \rightarrow \text{C} \equiv \text{C-CH}_2\text{CH}_2\text{CH}_3 + \text{Br}^- \]
The product Y is 3-hexyne (C₆H₁₀).

### Final Products
- **X**: 1-butyne (C₄H₆)
- **Y**: 3-hexyne (C₆H₁₀)

### Summary
Thus, the final answer is:
- X = 1-butyne
- Y = 3-hexyne