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Calculating percent purity from a reaction

One of the reactions that occurs in a blast furnace, where iron ore is converted to cast iron is Fe2O3 + CO = Fe + CO2.

Suppose that 1750 kg of Fe is obtained from a 2780 kg sample of Fe2O3. Assuming that the reaction goes to completion, what is he percent purity of Fe2O3 in the original sample?
I balanced the equation to get Fe2O3 +3CO= 2Fe + 3CO2. Then I calculated the moles of Fe obtained to compare to moles of Fe2O3, getting:
1750 kg of Fe X 1 mole Fe/56 g Fe = 31250 mol Fe
2780 kg of Fe2O3 X 1 mole Fe2O3/160 g Fe2O3 =17.38 g Fe2O3

So now I'm not exactly sure what the problem is asking for in asking for percent purity of Fe2O3- is it asking what the percent of Fe is in Fe2O3? It has to be set up as a ratio, but I just don't know where to go from here!
31250 mol Fe X (1 mol Fe2O3/2 mol Fe) X(17.38 g Fe2O3/ 1 mole Fe2O3)=???? huge #!

Solution Preview

In order to get percent purity, you will calculate number of moles of pure Fe you got out (31250, as you said).

Next, you change this to moles of Fe2O3, since the reaction ...

Solution Summary

In this solution we explore how to calculate percent purity, solving an example step-by-step!