Question

When the following equation is balanced properly under acidic conditions, what are the coefficients of the species shown?

BrO3- + ClO2 Br- + ClO3-

Water appears in the balanced equation as a  (reactant, product, neither) with a coefficient of . (Enter 0 for neither.)

How many electrons are transferred in this reaction?

Answer 1

Br in BrO3- has oxidation state of +5

Br in Br- has oxidation state of -1

So, Br in BrO3- is reduced to Br-

Cl in ClO2 has oxidation state of +4

Cl in ClO3- has oxidation state of +5

So, Cl in ClO2 is oxidised to ClO3-

Reduction half cell:

BrO3- + 6e- --> Br-

Oxidation half cell:

ClO2 --> ClO3- + 1e-

Balance number of electrons to be same in both half reactions

Reduction half cell:

BrO3- + 6e- --> Br-

Oxidation half cell:

6 ClO2 --> 6 ClO3- + 6e-

Lets combine both the reactions.

BrO3- + 6 ClO2 --> Br- + 6 ClO3-

Balance Oxygen by adding water

BrO3- + 6 ClO2 + 3 H2O --> Br- + 6 ClO3-

Balance Hydrogen by adding H+

BrO3- + 6 ClO2 + 3 H2O --> Br- + 6 ClO3- + 6 H+

This is balanced chemical equation in acidic medium

BrO₃^- + 6 ClO₂ + 3 H₂O --> Br^- + 6 ClO₃^- + 6 H⁺

1, 6, 1, 6

water appears as a reactant and coefficient is 3

6 electrons are transferred