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Antimony pentoxide (Sb2O5) is a chemical compound of antimony and oxygen. It always occurs in hydrated form, Sb2O5·nH2O.[citation needed] It contains antimony in the +5 oxidation state.
A 2521 (OTTO) Antimony pentoxide, 99.9% Cas 1314-60-9 - used as an ion-exchange resin and as a polymerization and oxidation catalyst.