How could "lithium metal"lithium metal reduce "ferrous bromide"ferrous bromide to give "iron metal"iron metal?

1 Answer
Dec 12, 2017

2Li + FeBr_2 rarr Fe + 2LiBr2Li+FeBr2Fe+2LiBr is the stoichiometric equation....

Explanation:

Fe(II)Fe(II) is reduced....

FeBr_2 +2e^(-) rarr Fe + 2Br^(-)FeBr2+2eFe+2Br (i)(i)

"Lithium metal"Lithium metal is oxidized....

Li rarr Li^+ + e^(-)LiLi++e (ii)(ii)

We add (i)(i) and (ii)(ii) together in such a way that the electrons are retired from the equation....(i)+2xx(ii)(i)+2×(ii)

2Li +FeBr_2 +2e^(-)rarr 2Li^+ +Fe + 2Br^(-)+ 2e^(-)2Li+FeBr2+2e2Li++Fe+2Br+2e

To give finally:

2Li +FeBr_2 rarr 2LiBr +Fe2Li+FeBr22LiBr+Fe

Both charge and mass are balanced as is absolutely required (and this is why we employ the oxidation number method).

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