In the sequence of reactions
`C_(6)H_(5)Broverset(Mg)underset("ether")rarr (X) overset((i)CO_(2))underset((iii)H_(3)O^(+))rarr(Y)` the product (Y) is

Options

A. biphenyl
B. m - bromobenzoic acid
C. benzoic acid
D. benzyl alcohol

Answer

To solve the question, we need to analyze the sequence of reactions step by step.

### Step 1: Identify the starting compound
The starting compound is phenyl bromide, which has the formula \( C_6H_5Br \).

### Step 2: Reaction with Magnesium and Ether
When phenyl bromide reacts with magnesium in an ether solvent, it forms a Grignard reagent. The reaction can be represented as:
\[ C_6H_5Br + Mg \xrightarrow{ether} C_6H_5MgBr \]
Here, \( C_6H_5MgBr \) is phenyl magnesium bromide, the Grignard reagent (denoted as \( X \)).

### Step 3: Reaction with Carbon Dioxide
Next, the Grignard reagent \( C_6H_5MgBr \) reacts with carbon dioxide (\( CO_2 \)). The nucleophilic carbon in the Grignard reagent attacks the electrophilic carbon in carbon dioxide:
\[ C_6H_5MgBr + CO_2 \rightarrow C_6H_5COO^- + MgBr^+ \]
This results in the formation of a carboxylate ion \( C_6H_5COO^- \).

### Step 4: Hydrolysis with Acid
The carboxylate ion formed in the previous step is then treated with a mineral acid (like \( H_3O^+ \)):
\[ C_6H_5COO^- + H_3O^+ \rightarrow C_6H_5COOH + OH^- \]
This hydrolysis leads to the formation of benzoic acid (\( C_6H_5COOH \)), which is the final product \( Y \).

### Final Answer
Thus, the product \( Y \) is benzoic acid, represented as:
\[ Y = C_6H_5COOH \]

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