Question

How do we represent the redox reaction between dichromate ion and ferrous ion stoichiometrically?

Answer 1

`Cr_2O_7^(2-) +6Fe^(2+) + 14H^(+) rarr2Cr^(3+)+6Fe^(3+)+7H_2O(l)`

Explanation:

`"Reduction half-equation"`

`Cr_2O_7^(2-) +14H^(+) + 6e^(-) rarr2Cr^(3+)+7H_2O(l)`

`"Oxidation half-equation"`

`Fe^(2+) rarrFe^(3+)+e^(-)`

And so we takes one of the former and six of the latter......

`Cr_2O_7^(2-) +6Fe^(2+) + 14H^(+) rarr2Cr^(3+)+6Fe^(3+)+7H_2O(l)`