Which degree of alkyl halide is Most reactive towards `E2` mechanism`:`

Explanation

To determine which degree of alkyl halide is most reactive towards the E2 mechanism, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding E2 Mechanism**:
- The E2 mechanism stands for bimolecular elimination. In this mechanism, both the alkyl halide and the base are involved in the rate-determining step.

2. **Breaking Bonds**:
- During the E2 reaction, two bonds are broken simultaneously: a carbon-hydrogen (C-H) bond and a carbon-halogen (C-X) bond. This leads to the formation of a double bond between the carbon atoms.

3. **Rate of Reaction**:
- The rate of the E2 reaction depends on the concentration of both the alkyl halide and the base. Therefore, it is classified as a bimolecular reaction.

4. **Reactivity Order of Alkyl Halides**:
- The reactivity of alkyl halides in E2 reactions follows a specific order based on their degree:
- Tertiary (3°) > Secondary (2°) > Primary (1°)
- This means that tertiary alkyl halides are the most reactive towards the E2 mechanism, followed by secondary, and then primary alkyl halides.

5. **Conclusion**:
- Therefore, the degree of alkyl halide that is most reactive towards the E2 mechanism is the tertiary alkyl halide.

### Final Answer:
The most reactive degree of alkyl halide towards the E2 mechanism is **tertiary (3°) alkyl halide**.

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