Most stable carbocation formed from `(CH_(3))_(3)C-Br,(C_(6)H_(5))_(3)CBr,(C_(6)H_(5))_(2)CHBr` and `C_(6)H_(5)CH_(2)Br` would be

Options

A. `C_(6)H_(5)overset(o+)(CH_(2))`
B. `(CH_(3))_(3)overset(o+)(C)`
C. `(C_(6)H_(5))_(3)overset(o+)(C)`
D. `(C_(6)H_(5))_(2)overset(o+)(CH)`

Answer

To determine the most stable carbocation formed from the given compounds: (CH₃)₃C-Br, (C₆H₅)₃CBr, (C₆H₅)₂CHBr, and C₆H₅CH₂Br, we need to analyze the stability of the carbocations that can be formed from each compound.

### Step 1: Identify the Carbocations
1. **(CH₃)₃C-Br**: This will form the carbocation (CH₃)₃C⁺, which is a tertiary carbocation.
2. **(C₆H₅)₃CBr**: This will form the carbocation (C₆H₅)₃C⁺, which is a carbocation with three phenyl groups attached to the positively charged carbon.
3. **(C₆H₅)₂CHBr**: This will form the carbocation (C₆H₅)₂CH⁺, which is a secondary carbocation with two phenyl groups.
4. **C₆H₅CH₂Br**: This will form the carbocation C₆H₅CH₂⁺, which is a primary carbocation with one phenyl group.

### Step 2: Analyze Stability Factors
The stability of carbocations can be influenced by:
- **Inductive Effect**: Alkyl groups donate electron density, stabilizing the positive charge.
- **Hyperconjugation**: The presence of adjacent C-H bonds can help stabilize the positive charge.
- **Resonance**: The ability of the positive charge to be delocalized over adjacent π systems (like phenyl rings) greatly enhances stability.

### Step 3: Evaluate Each Carbocation
1. **(CH₃)₃C⁺**: Tertiary carbocation, stabilized by hyperconjugation and inductive effect from three methyl groups.
2. **(C₆H₅)₃C⁺**: Carbocation stabilized by resonance from three phenyl groups, allowing for significant delocalization of the positive charge.
3. **(C₆H₅)₂CH⁺**: Secondary carbocation, stabilized by resonance from two phenyl groups, but less than (C₆H₅)₃C⁺.
4. **C₆H₅CH₂⁺**: Primary carbocation, only slightly stabilized by resonance from one phenyl group.

### Step 4: Conclusion
Among the carbocations analyzed, the one with the highest stability is **(C₆H₅)₃C⁺** due to the extensive resonance stabilization provided by the three phenyl groups.

Thus, the most stable carbocation formed from the given compounds is **(C₆H₅)₃C⁺**.

### Final Answer
The most stable carbocation is **(C₆H₅)₃C⁺** (Option C).

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