14.5 a-ox numbers

[sofiakavanaugh]

Hi,

For part a of question 14, the reaction is O3(aq) + Br-(aq) --> O2(g) + BrO3-(aq)
The bromine is going from -1 to +5 so its losing electrons, therefore being oxidized, but the oxygen appears not to change oxidation numbers ( 0 to 0). I understand if one is being oxidized its logical that the other would be reduced but it just seems weird since the oxygens oxidation numbers are not changing. Can someone please explain this? Does this have to do with the fact that it is in basic solution? But still that wouldn't change the oxygen's oxidation numbers I don't think?

Thanks

[Lucian1F]

The oxygen that is bonded to the bromine got reduced to -2