# 2H^+ (aq) + BrO2^-(aq) + BrO3^- (aq) <--> 2BrO2(aq) +H2O(I)  Like many reactions in living cells, all three reactions specified are redox reactions.  Identify the species being oxidized and...

2H^+ (aq) + BrO2^-(aq) + BrO3^- (aq) <--> 2BrO2(aq) +H2O(I)

Like many reactions in living cells, all three reactions specified are redox reactions.  Identify the species being oxidized and the species being reduced in the reaction.

mlsiasebs | College Teacher | (Level 1) Associate Educator

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An oxidation-reduction reaction, or redox reaction, occurs when electrons are transferred from one species to another.  You must always have a reduction and an oxidation reaction in pairs.  Neither can happen alone.

To determine what is oxidized in reduced, we first need to look at the oxidation numbers for each species

H+ --> +1 because oxidation number is the same as the charge

Br (in BrO2-) --> +3 because each oxygen is -2 and we need Br to be +3 so that the sum of the oxidation numbers equals -1

O --> -2

Br (in BrO3-) --> +5 (see note for BrO2-)

O --> -2

Br (in BrO2) --> +4 (because the sum of oxidation numbers must be zero for a neutral compound)

O --> -2

H --> +1

O --> -2

To find the reduced species, we need to find the reaction that occurs from the accepting of an electron (i.e. the oxidation number is reduced) so BrO3- is reduced to BrO2 because it goes from +5 to +4

To find the oxidized species, we need to find the reaction that occurs from the donation of an electron (i.e. the oxidation number increases) so BrO2- is oxidized to BrO2 because it goes from +3 to +4.