Electrophilic addition reactions proceed in two steps. The first step involves the addition of an electrophile. Name the type of intermediate formed in the first step of the following addition reaction.
`H_(3)C -HC=CH_(2)+ H^(+)to`?

Options

A. `2^(@)` carbanion
B. `1^(@)` carbocation
C. `2^(@)` carbocation
D. `1^(@)` carbanion

Explanation

To solve the question regarding the electrophilic addition reaction and the type of intermediate formed, we can break it down into the following steps:

### Step 1: Identify the Reaction
The reaction given is:
\[ H_{3}C - HC = CH_{2} + H^{+} \]

This indicates that we have an alkene (propene) reacting with a proton (H⁺), which is an electrophile.

**Hint:** Look for the electrophile in the reaction and identify the alkene.

### Step 2: Understand Electrophilic Addition
In electrophilic addition reactions, the first step involves the addition of an electrophile (in this case, H⁺) to the double bond of the alkene. This leads to the formation of an intermediate.

**Hint:** Recall that electrophiles are electron-deficient species that seek electrons.

### Step 3: Determine the Site of Electrophile Attack
According to Markovnikov's rule, the electrophile (H⁺) will add to the carbon atom of the double bond that has the greater number of hydrogen atoms. In propene, the double bond is between the first and second carbon atoms.

**Hint:** Apply Markovnikov's rule to decide where the H⁺ will add.

### Step 4: Form the Intermediate
When H⁺ adds to the second carbon (which has more hydrogen atoms), it leads to the formation of a carbocation at the first carbon. The structure of the intermediate can be represented as follows:
\[ CH_{3} - C^{+}H - CH_{2} \]
This indicates that a secondary carbocation is formed.

**Hint:** Remember that carbocations are positively charged intermediates formed during electrophilic addition.

### Step 5: Identify the Type of Intermediate
The intermediate formed in this reaction is a carbocation. Specifically, it is a secondary carbocation because the positively charged carbon is attached to two other carbon atoms.

**Hint:** Classify the carbocation based on the number of carbon atoms attached to the positively charged carbon.

### Final Answer
The type of intermediate formed in the first step of the addition reaction is a **secondary carbocation**.

---