leaving group ability

Question

Best leaving group among given (in SN1):

RankGuru · Accepted Answer

1. **Criteria**: A good leaving group must be able to stabilize the negative charge after it departs. 2. **Basicity**: Weaker bases are better leaving groups. The order of acidity of hydracids is $HI > HBr > HCl > HF$. 3. **Conjugate Bases**: Therefore, the order of basic strength is $I^- < Br^- < Cl^- < F^-$. 4. **Size and Polarizability**: Iodide ($I^-$) is the largest and most polarizable. It can spread the negative charge over a much larger volume than the small Fluoride ion. 5. **Bond Strength**: The $C-I$ bond is the longest and weakest, making its cleavage easier. 6. **Ranking**: **$I^- > Br^- > Cl^- > F^-$**.

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leaving group ability

Select the correct option: