The carbocation is the intermediate in

Options

A. `E_(2)`
B. `E_(1)`
C. `S_(N)` Ar
D. Both (2) & (3)

Answer

To answer the question "The carbocation is the intermediate in", we need to analyze the types of reactions where carbocations are formed as intermediates.

### Step-by-Step Solution:

1. **Understanding Carbocations**:
- A carbocation is a positively charged carbon atom that has only six electrons in its valence shell. It is an important intermediate in various organic reactions.

2. **Identifying Reaction Types**:
- There are two main types of reactions where carbocations can form:
- **E1 elimination reactions**
- **SN1 nucleophilic substitution reactions**

3. **E1 Elimination Reaction**:
- In an E1 reaction, the first step involves the formation of a carbocation intermediate. This occurs when a leaving group departs, resulting in a positively charged carbon atom.
- The second step involves the loss of a proton (H+) from the carbocation to form an alkene.

4. **SN1 Nucleophilic Substitution Reaction**:
- Similarly, in an SN1 reaction, the first step also involves the formation of a carbocation when the leaving group departs.
- The second step involves a nucleophile attacking the carbocation to form a new bond.

5. **Conclusion**:
- Therefore, the correct answer to the question is that the carbocation is the intermediate in both **E1 elimination reactions** and **SN1 nucleophilic substitution reactions**. However, since the question asks for a specific context, we can conclude that the carbocation is most notably an intermediate in **E1 reactions**.

### Final Answer:
The carbocation is the intermediate in **E1 elimination reactions**.