Why ICI is more reactive than `I_2` ?

Explanation

Interhalogen compounds are heteroatomic in nature. In these compounds, the different halogen atoms are linked by covalent bonds. Because of the electronegativity difference, these compounds are polar in nature and are more reactive than halogens. In pure halogens, there is no electronegativity difference. Hence, the halogens are non-polar in nature.