What are the oxidation number of the underlined elements in each of the following and how do you rationalise your results?

KI3

In KI3, O.N. of Kis + 1. Hence, the average O.N. is


However, O.N. cannot be fractional. Therefore, we will have to consider the structure of KI3 to find the oxidation states.


In KI3 molecule, an atom of iodine forms a coordinate covalent bond with an iodine molecule.



Hence, in a KI3 molecule, the O.N. of the two I atoms forming the I2 molecule is 0, wherein the O.N. of the I atom forming the coordinate bond is -1.


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