Redox equations are balanced either by ion-electron method or by oxidation number method. Both methods lead to the correct from of the balanced equation. The ion electron methodd has two advantages. So some chemists prefer to use the ion-electron method for redox reactions carried out in dilute aqueous solutions, where free ions have more or less independent existance.
The oxidation state method for redox reactions is mostly used for solid chemicals or for reactions in concentrated acid media.
For the reaction
`FeS_(2)rarrFe^(3+)+SO_(2)`
the `n`-factor is

Options

A. `1`
B. `11`
C. `28`
D. `61`

Answer

B

Explanation

`{:(Fe^(2+) rarr Fe^(3+) + e^(-)),(S_(2)^(2-) rarr 2SO_(2)+10e^(-)),(2x=-2" "2x-8=0),(2x=8)]^("Tota"l" "e^(-)=11)`