1. An iron ore sample is a mixture of Fe2O3 and several impurities. A 752. g sample of the impure iron ore is heated with excess carbon. Only the Fe2O3 present in the ore reacts with the carbon producing 341. g of carbon monoxide by the following reaction. What is the mass percentage of Fe2O3 in the impure iron ore sample?
Fe2O3 + 3C --------> 2Fe + 3CO
2007-12-02 08:30:52 · 1 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
heeeey.
im not sure how to reply to you because i havent used this hardly.
i kinda understand, but when i try to do the math im not getting the right answer.
i know how to get the number of grams of each substance etc etc.
and i understand how to find the mass percent, but for some reason i'm just not getting the right answer.
:(
2007-12-02 09:17:41 · update #1
Bookkeeping, and as always when balancing different substances, you have to use moles and the balanced equation.
The balanced equation gives you the exchange rate between moles of different substances; in this case, CO and Fe2O3.
You know the mass of CO. Divide by formula weight of CO to get moles CO.
Balanced equation tells you that 3 mol CO were formed from each mole Fe2O3. So you can now work out moles Fe2O3.
Almost home and dry now. Multiply by molar mass of Fe2O3 to get grams Fe2O3.
(grams Fe2O3)/(752 g in sample) x 100% = percent Fe2O3 in sample. All done.
Does that help?
2007-12-02 08:43:40 · answer #1 · answered by Facts Matter 7 · 0⤊ 0⤋