`underset((A))underset("Propa-1,2-diene")(Coverset(3)(H)_(2)=overset(2)(C)=overset(1)(C)H_(2))overset(NaNH_(2)+Liq.NH_(3))(rarr)(B)`
Which of the following statements is `//` are correct ?

Options

A. Product `(B)` is `CH_(2)=CH-CH_(3).`
B. Product `(B)` is propyne.
C. Product `(B)` is more stable than `(A)`
D. Compound `(A)` has a more negative heat of hydrogenation than the compound `(B)`

Explanation

To solve the question regarding the reaction of propa-1,2-diene (compound A) with sodium amide (NaNH₂) in liquid ammonia (NH₃) to form compound B, we can follow these steps:

### Step 1: Identify the Reactant
The reactant is propa-1,2-diene, which has the structure:
\[ \text{CH}_2=CH-CH_2 \]
This compound has two double bonds between the first and second carbon atoms and the second and third carbon atoms.

### Step 2: Understand the Reaction Conditions
The reaction involves sodium amide (NaNH₂) in liquid ammonia (NH₃). Sodium amide is a strong base and will deprotonate the terminal hydrogen atoms of the diene.

### Step 3: Mechanism of Reaction
When NaNH₂ is added to propa-1,2-diene, the following occurs:
- The base (NH₂⁻) attacks one of the terminal hydrogen atoms, resulting in the formation of a carbanion intermediate.
- This carbanion can then rearrange or react further, leading to the formation of a triple bond.

### Step 4: Formation of the Product
The product formed from this reaction is propyne (C₃H₄), which has the structure:
\[ \text{CH}_3-C \equiv C-H \]
This indicates that the reaction converts the diene into an alkyne.

### Step 5: Stability and Heat of Hydrogenation
- Alkynes (like propyne) are generally more stable than cumulative dienes (like propa-1,2-diene).
- The heat of hydrogenation is a measure of stability; more stable compounds have less negative heat of hydrogenation. Therefore, propyne will have a more negative heat of hydrogenation compared to propa-1,2-diene.

### Step 6: Evaluate the Statements
Now, we can evaluate the statements given in the question:
1. **Product B is propyne** - This statement is correct.
2. **Product B is more stable than compound A** - This statement is also correct, as alkynes are more stable than cumulative dienes.
3. **Compound A has more negative heat of hydrogenation** - This statement is incorrect because propyne (compound B) has a more negative heat of hydrogenation than propa-1,2-diene.

### Conclusion
The correct statements are:
- Product B is propyne.
- Product B is more stable than compound A.