Addition of HCN to ethyne in presence of `Ba(CN)_(2)` as catalyst gives-

Options

A. Ethyl cyanide
B. 1,1 - dicyano ethane
C. Divinyl cyanide
D. Vinyl cyanide

Answer

To solve the question regarding the addition of HCN to ethyne in the presence of Ba(CN)₂ as a catalyst, we can follow these steps:

### Step 1: Identify the Reactants
The reactants in this reaction are:
- Ethyne (C₂H₂), which can be represented as CH≡CH.
- Hydrogen cyanide (HCN).

### Step 2: Understand the Role of the Catalyst
Ba(CN)₂ acts as a catalyst in this reaction. Catalysts are substances that speed up a chemical reaction without being consumed in the process. In this case, Ba(CN)₂ facilitates the addition of HCN to ethyne.

### Step 3: Write the Reaction
The addition of HCN to ethyne can be represented as follows:
\[ \text{CH} \equiv \text{CH} + \text{HCN} \xrightarrow{\text{Ba(CN)}_2} \text{CH}_2\text{CH} \text{C} \equiv \text{N} \]

### Step 4: Identify the Product
The product formed from this reaction is:
- CH₂=CH-C≡N, which is known as vinyl cyanide.

### Step 5: Conclusion
Thus, the addition of HCN to ethyne in the presence of Ba(CN)₂ as a catalyst yields vinyl cyanide.

### Final Answer
The correct answer is vinyl cyanide.

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