Question

Write a balanced chemical equation describing the oxidation of bromine liquid by the manganese (III) to form the bromate ion and manganese (II) in an acidic aqueous solution. Use the smallest whole number coefficients possible.

Answer 1

Br2(l) --> BrO3-(aq)

Mn+3(aq) --> Mn+2(aq)

in acidic solution:

balance Br

Br2(l) --> 2BrO3-(aq)

Mn+3(aq) --> Mn+2(aq)

balance O

6H2O + Br2(l) --> 2BrO3-(aq)

Mn+3(aq) --> Mn+2(aq)

balance H+

6H2O + Br2(l) --> 2BrO3-(aq) + 12H+

Mn+3(aq) --> Mn+2(aq)

balance charges

6H2O + Br2(l) --> 2BrO3-(aq) + 12H+ +10e-

1e-+ Mn+3(aq) --> Mn+2(aq)

balance e-

6H2O + Br2(l) --> 2BrO3-(aq) + 12H+ +10e-

10e-+ 10Mn+3(aq) --> 10Mn+2(aq)

add all

10e-+ 10Mn+3(aq) + 6H2O + Br2(l) --> 2BrO3-(aq) + 12H+ +10e- + 10Mn+2(aq)

cancel common terms

10Mn+3(aq) + 6H2O + Br2(l) --> 2BrO3-(aq) + 12H+ 10Mn+2(aq)