Question

In which of the following compounds, the
oxidation number of iodine is fractional ?
(a) IF₇ (b) I₃⁻
(c) IF₅ (d) IF₃

Answer 1

The answer is (d) IF₃..........

Answer 2

(b) I₃⁻

Explanation:

Oxidation number of Iodine is as follows:

IF7 : x +7 *(−1) = 0; x = 7

I-3 : x *3 = −1; x = −1/3

IF5 : x +5 *(−1) = 0; x = 5

IF3 : x +3 *(−1)  = 0; x = 3

We find that the oxidation number of I is fractional, -1/3.

Option B is the answer.