The case of dehydrohalogenation for different halogensis in the order

Options

A. lodide `gt` Bromide `gt` Chloride
B. Bromide `gt` lodide `gt` Chloride
C. Chloride `gt` Bromide `gt` lodide
D. lodide `gt` Chloride `gt` Bromude

Explanation

To determine the order of dehydrohalogenation for different halogens, we need to analyze the leaving groups involved in the reaction. The process of dehydrohalogenation involves the elimination of a hydrogen atom and a halogen atom from an alkyl halide, resulting in the formation of a double bond.

### Step-by-Step Solution:

1. **Understand Dehydrohalogenation**:
- Dehydrohalogenation is an elimination reaction where a hydrogen atom and a halogen atom (denoted as X) are removed from adjacent carbon atoms in a substrate, leading to the formation of a carbon-carbon double bond.

2. **Identify the Halogens**:
- The halogens we are considering are Iodine (I), Bromine (Br), and Chlorine (Cl).

3. **Evaluate Leaving Group Ability**:
- The effectiveness of a halogen as a leaving group is crucial for the reaction. A good leaving group will be able to depart easily from the substrate.
- The order of leaving group ability is generally: Iodide (I⁻) > Bromide (Br⁻) > Chloride (Cl⁻).

4. **Explain the Order**:
- Iodide is the best leaving group because it is larger and the bond between iodine and carbon is weaker, making it easier for it to leave.
- Bromide is a better leaving group than chloride, but not as good as iodide.
- Chloride is the least effective leaving group among the three due to its smaller size and stronger bond with carbon.

5. **Conclusion**:
- Therefore, the order of dehydrohalogenation based on the halogens is:
- Iodide (I) > Bromide (Br) > Chloride (Cl).

### Final Answer:
The order of dehydrohalogenation for different halogens is: **Iodide (I) > Bromide (Br) > Chloride (Cl)**.