Which of the following balanced chemical reactions does NOT represent a valid oxidation-reduction (r — Redox Reactions and Volumetric Analysis Chemistry Question

💡 Solution & Explanation

In $BaO_2 + H_2SO_4 \to BaSO_4 + H_2O_2$ , the oxidation state of Barium remains rigidly $+2$ . Oxygen is structurally present as a peroxide ion ( $O_2^{2-}$ ) in both the reactant $BaO_2$ and the product $H_2O_2$ , so its oxidation state remains statically $-1$ . Sulphur remains $+6$ . Since no electrons are transferred between species, it is exclusively a simple double displacement (metathesis) reaction. All other options clearly display elements changing oxidation states.