The oxidation number of iodine in I^- (aq) is -1. In I2 (s), the oxidation number of iodine is 0 because it is in its elemental form. Therefore, there is an increase in the oxidation number of iodine by 1.
The correct answer is b) an increase of 1.
What is the change in oxidation number of an atom of iodine in the half-reaction I ^- (aq) → I2 (s)?
a) an decrease of 1
b) a increase of 1
c) an decrease of 2
d) a increase of 2
e) an decrease of 3
1 answer