Concept:Chemical reactivity in haloalkanes requires breaking the carbon-halogen bond. A weaker bond requires less activation energy to break, resulting in a faster, more reactive molecule.
Solution:- The size of the halogen atom increases down the periodic table: F < Cl < Br < I.
- As the atomic radius increases, the orbital overlap with the small carbon atom becomes much poorer, making the bond longer and weaker.
- The C-I bond has the lowest bond dissociation energy (weakest bond) among all alkyl halides.
- Because it breaks so easily, iodo-compounds are highly unstable and exceptionally reactive compared to the other halogens.
Why other options are incorrect:- Option D: Fluoro-compounds have the shortest and strongest bonds, making them incredibly stable and generally unreactive under normal conditions.
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