The intermediate during the addition of `HCl` to propene in the presence of peroxide is :

Options

A. `CH_(3)`-CH - `CH_(3)` -Cl
B. `CH_(3) - overset(+)(CH) - CH_(3)`
C. `CH_(3) - CH_(2) - CH_(2)`
D. `CH_(3) - CH_(2) - overset(+)(CH_(2))`

Answer

To determine the intermediate formed during the addition of HCl to propene in the presence of peroxide, we need to analyze the reaction step-by-step.

### Step 1: Understanding the Reaction
When HCl is added to propene (CH2=CH-CH3), it can undergo an electrophilic addition reaction. The presence of peroxide is important to consider, but in the case of HCl, it does not lead to the formation of free radicals, unlike with HBr.

**Hint:** Remember that the peroxide effect is significant for HBr but not for HCl.

### Step 2: Breaking Down HCl
HCl dissociates into H⁺ and Cl⁻ ions. The H⁺ ion acts as an electrophile and will attack the double bond of propene.

**Hint:** Identify the electrophile in the reaction.

### Step 3: Markovnikov's Rule
According to Markovnikov's rule, the electrophile (H⁺) will attach to the carbon atom with the greater number of hydrogen atoms. In propene, the double bond is between the first and second carbon atoms. The first carbon (C1) has two hydrogens, while the second carbon (C2) has one hydrogen.

**Hint:** Recall that Markovnikov's rule helps predict the more stable carbocation formation.

### Step 4: Formation of Carbocation
When H⁺ adds to C1, it results in a secondary carbocation at C2 (CH3-CH⁺-CH2Cl). Alternatively, if H⁺ were to add to C2, it would lead to a less stable primary carbocation at C1 (CH3-CH2-CH⁺-Cl).

**Hint:** Compare the stability of the carbocations formed.

### Step 5: Stability of Carbocations
The secondary carbocation (formed at C2) is more stable than the primary carbocation (formed at C1) due to hyperconjugation and the inductive effect from the adjacent carbon atoms.

**Hint:** Remember that tertiary > secondary > primary in terms of carbocation stability.

### Step 6: Conclusion
The intermediate formed during the addition of HCl to propene in the presence of peroxide is a secondary carbocation (CH3-CH⁺-CH2Cl).

### Final Answer
The intermediate is a secondary carbocation.

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