A mixture of FeBry and inert material is analyzed to determine the Fe content. First the mixture is dissolved in water. Then all of the bromide ion is precipitated as AgBr by the addition of an excess of silver nitrate.

FeBr(aq) + 3AgN0(aq) ->3AgBr(s) + Fe(NO3)(aq)

In one experiment, a 0.6118 g sample of the mixture resulted in 0.8553 g of AgBr. Determine the percent (by mass) of Fe in the mixture.