If acetic acid reacts with methyl alcohol containing labelled oxygen atom in presence of dry HCl.The labeled oxygen atom, at the complete reaction will be found in

Options

A. Methyl acetate
B. water
C. Methyl alcohol
D. acetic acid

Explanation

To solve the question, we need to analyze the reaction between acetic acid and methyl alcohol in the presence of dry HCl, focusing on the fate of the labeled oxygen atom from methyl alcohol.

### Step-by-Step Solution:

1. **Identify the Reactants**:
- Acetic acid (CH₃COOH)
- Methyl alcohol (CH₃OH) with a labeled oxygen atom (let's denote it as O*)

2. **Understand the Role of Dry HCl**:
- Dry HCl acts as a catalyst in this reaction. The H⁺ ions from HCl will protonate the oxygen atom in methyl alcohol, making it a better nucleophile.

3. **Protonation of Methyl Alcohol**:
- The labeled oxygen in methyl alcohol (O*) gets protonated, forming CH₃OH₂⁺ (protonated methyl alcohol).

4. **Nucleophilic Attack**:
- The protonated methyl alcohol (CH₃OH₂⁺) will then attack the carbonyl carbon of acetic acid (CH₃COOH). This leads to the formation of a tetrahedral intermediate.

5. **Formation of Tetrahedral Intermediate**:
- The tetrahedral intermediate will have the structure:
- CH₃C(OH)(OCH₃) (where OCH₃ contains the labeled oxygen O*).

6. **Proton Transfer and Elimination of Water**:
- The hydroxyl group (OH) in the tetrahedral intermediate can be protonated again, leading to the elimination of water (H₂O) and forming the ester.

7. **Final Product Formation**:
- The final product of this reaction is methyl acetate (CH₃COOCH₃), which contains the labeled oxygen atom (O*) from the methyl alcohol.

8. **Conclusion**:
- The labeled oxygen atom will be found in the final product, which is methyl acetate.

### Final Answer:
The labeled oxygen atom will be found in **methyl acetate**.