Which of the following statement(s) is/are not true about the following decomposition reaction?
2KClO3→ 2KCl + 3O2
(i) Potassium is undergoing oxidation
Potassium has a general oxidation number of +1 as it as a group 1 alkali member. In KClO3 and KCl the charge on potassium does not change so it is not going under oxidation but has same ON in both the compounds.
(ii) Chlorine is undergoing oxidation
The oxidation number of Cl in KClO3 is
→ 
And that in KCl is -1, so the change is from +5 to -1 which shoes reduction in oxidation number thus the statement is wrong.
(iii) Oxygen is reduced
As only atom having high electronegativity in periodic table is F, only with fluorine compounds oxygen shows positive charge or oxidation number, thus oxygen here is not reduced as also justified that both reactant and product oxygen molecule shows -2 oxidation number.