The reaction of `CH_(3)MgBr` on dry ice followed by acid hydrolysis gives

Options

A. acetic acid
B. formic acid
C. acetone
D. acetaldehyde

Answer

To solve the question regarding the reaction of `CH₃MgBr` (a Grignard reagent) with dry ice followed by acid hydrolysis, we can break it down into a series of steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
The reactants in this reaction are `CH₃MgBr` (methylmagnesium bromide) and dry ice (solid carbon dioxide, `CO₂`).

2. **Understanding the Grignard Reagent**:
`CH₃MgBr` is a Grignard reagent, which means it has a carbon atom that is nucleophilic (electron-rich) due to the presence of the magnesium atom. The `CH₃` group carries a partial negative charge, while the `MgBr` part carries a partial positive charge.

3. **Reaction with Dry Ice**:
When `CH₃MgBr` reacts with dry ice, the nucleophilic `CH₃` group attacks the electrophilic carbon in `CO₂`. This results in the formation of a carboxylate intermediate:
\[ CH₃MgBr + CO₂ \rightarrow CH₃C(=O)O^{-}MgBr^{+} \]
Here, `CH₃C(=O)O^{-}` is the carboxylate ion, and `MgBr` is the magnesium bromide ion.

4. **Acid Hydrolysis**:
The next step is acid hydrolysis. When the carboxylate ion is treated with an acid (like `H₂O` or `HCl`), it protonates the carboxylate ion to form a carboxylic acid:
\[ CH₃C(=O)O^{-} + H^{+} \rightarrow CH₃C(=O)OH \]
The product formed here is `CH₃C(=O)OH`, which is ethanoic acid (or acetic acid).

5. **Final Product**:
The final product of the reaction is therefore ethanoic acid, which can also be represented as `CH₃COOH`.

### Conclusion:
The reaction of `CH₃MgBr` on dry ice followed by acid hydrolysis yields **ethanoic acid (acetic acid)**.