[alanjz]

Which oxide is the best reducing agent?
(A) CO₂
(B) NO₂
(C) SiO₂
(D) SO₂

Why is the answer D? I assume they're all oxidized to XO₄ but I don't understand why S, the most electronegative out of the four, makes SO₂ the best reducing agent.

[Needaask]

Are you asking that since S is so electronegative (compared to the other atoms) it should have more trouble giving up electrons than the rest right?

[Borek]

I assume they're all oxidized to XO₄

None of them is oxidized to SO₄. And electronegativity has nothing to do with this question - it is more about possible oxidation states.

[Needaask]

I assume they're all oxidized to XO₄

None of them is oxidized to SO₄. And electronegativity has nothing to do with this question - it is more about possible oxidation states.

Oh because sulfur can have an expanded octet? But why wouldn't electronegativity play a role here?