Question

Label which elements are the: oxidized, oxidizing agent, reduced, reducing agents? 2FeBr2 + Br2 ----> 2FeBr3

Answer 1

Well let us supply some oxidation numbers to the stoichiometric equation. An increase in oxidation number denotes OXIDATION, and a decrease specifies reduction....

Explanation:

We gots `"iron(II)"` oxidized up to give `"iron(III)"`...and so we write the oxidation half-equation as...

`Fe^(2+) rarr Fe^(3+) + e^(-)` `(i)`

And elemental bromine, `stackrel(0)Br_2` is REDUCED to `Br^(-)`

`1/2Br_2(l) + e^(-) rarr Br^(-)` `(ii)`

Given the one electron transfer, we simply adds `(i)+(ii)`...and throw in TWO `Br^(-)` ions either side....bromine is here the oxidizing agent (because it accepts electrons), and ferrous ion is the reducing agent because it is oxidized and is the source of such electrons....

`Fe^(2+)+1/2Br_2(l)+2Br^(-) + e^(-) rarr Fe^(3+) + 3Br^(-)+e^(-)`

...and we get after cancellation....

`Fe^(2+)+1/2Br_2(l)+2Br^(-) rarr FeBr_3`

Happy?