Which of the following is formed when acetonitrile is hydrolysed partially with cold conc `HCI` ? .

Options

A. Acetic acid
B. Acetamide
C. Methyl cyanide
D. Acetic anhydride

Explanation

To solve the question of what is formed when acetonitrile is hydrolyzed partially with cold concentrated HCl, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**: The reactant given is acetonitrile, which has the chemical formula CH₃C≡N.

2. **Understand the Hydrolysis Process**: Hydrolysis involves the reaction of a compound with water (H₂O) to form new products. In this case, we are using cold concentrated HCl, which provides H⁺ ions and Cl⁻ ions in solution.

3. **Write the Reaction**: The reaction can be represented as:
\[ \text{CH}_3\text{C} \equiv \text{N} + \text{HCl} + \text{H}_2\text{O} \rightarrow \text{CH}_3\text{C}(O)\text{NH}_2 + \text{HCl} \]
Here, the acetonitrile is partially hydrolyzed to form an amide.

4. **Identify the Product**: The product formed from the partial hydrolysis of acetonitrile is acetamide (CH₃C(O)NH₂). This is because the nitrile group (C≡N) is converted to an amide group (C(O)NH₂).

5. **Conclusion**: The final product of the reaction is acetamide.

### Final Answer:
The compound formed when acetonitrile is hydrolyzed partially with cold concentrated HCl is **acetamide (CH₃C(O)NH₂)**.

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