Consider the fallowing statement :
(I) `CH_3OC^(o+)H_2` is more stable that `CH_3CH_2^(o+)`
(II) `Me_3C^(o+)` is more stable than `CH_3CH_2C^(o+)H_2`
(III) `CH_2=CH-C^(o+)H_2` is more stable than `CH_3CH_2C^(o+)H_2`
(IV) `CH_2=C^(o+)H` is more stable thn `CH_3C^(o+)H_2` of these statement:

Options

A. I and II are correct
B. III and IV are correct
C. I,II and III are correct
D. All are correct

Answer

To analyze the stability of the given cations, let's evaluate each statement one by one.

### Step 1: Evaluate Statement I
**Statement I:** `CH3OC^(o+)H2` is more stable than `CH3CH2^(o+)`.

- The cation `CH3OC^(o+)H2` has an oxygen atom with a lone pair of electrons. This lone pair can participate in resonance, stabilizing the positive charge by delocalization.
- In contrast, `CH3CH2^(o+)` is a primary carbocation, which lacks resonance stabilization and is less stable.

**Conclusion:** Statement I is correct.

### Step 2: Evaluate Statement II
**Statement II:** `Me3C^(o+)` is more stable than `CH3CH2C^(o+)H2`.

- `Me3C^(o+)` (tertiary carbocation) has three methyl groups that can donate electron density through the +I effect, increasing its stability.
- `CH3CH2C^(o+)H2` is a primary carbocation, which is less stable due to the lack of significant electron-donating groups.

**Conclusion:** Statement II is correct.

### Step 3: Evaluate Statement III
**Statement III:** `CH2=CH-C^(o+)H2` is more stable than `CH3CH2C^(o+)H2`.

- The cation `CH2=CH-C^(o+)H2` is an allylic cation, which can be stabilized by resonance. The positive charge can be delocalized between the adjacent double bond and the cation.
- `CH3CH2C^(o+)H2` is a primary carbocation, which is less stable and lacks resonance stabilization.

**Conclusion:** Statement III is correct.

### Step 4: Evaluate Statement IV
**Statement IV:** `CH2=C^(o+)H` is more stable than `CH3C^(o+)H2`.

- `CH2=C^(o+)H` is a vinylic cation, which is highly unstable because the positive charge is on a carbon that is part of a double bond.
- `CH3C^(o+)H2` is a more stable secondary carbocation, as it has more hyperconjugation and is not involved in a double bond.

**Conclusion:** Statement IV is incorrect.

### Final Conclusion
The correct statements are I, II, and III. Therefore, the answer is that statements I, II, and III are correct.

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