Question

Which among the following halogen does not form polyhalide ion?

• A. Cl
• B. Br
• C. I
• D. F

Hint:

Polyhalide ion formation increases down the halogen group.

Answer 1

The Correct Option is D

Step 1: Understand polyhalide ions.
Polyhalide ions are formed when a halide ion combines with a halogen molecule, for example: \[ \text{I}^- + \text{I}_2 \rightarrow \text{I}_3^- \] Step 2: Analyze halogens.
Chlorine, bromine, and iodine can form polyhalide ions due to their larger atomic size and availability of vacant orbitals.
Step 3: Reason for fluorine.
Fluorine has very small size, very high electronegativity, and no vacant d-orbitals, so it does not form polyhalide ions.
Step 4: Conclusion.
Therefore, fluorine does not form polyhalide ions.