Question

why so2 can act as both oxidizing as well as reducing agent?

Answer 1

$SO_{2}$ can act as both oxidizing as well as reducing agent since it has +4 oxidation state which is exactly between its highest oxidation state +6 and lowest oxidation state +2 ,Thus  it can change its oxidation number either from +4 to-2(reduction) and +4 to+6 (oxidation) .

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