If 6.575g of iron metal are mixed with 3.897 g of oxygen gas,what is the theoretical yield of iron(lll) oxide?

Question

I need help with this chem prb!!!
I know the ans. which is 9.400 but i dont understand how they got this ans. cant figure it out :(
can someone tell me how to do this prb thankz!

Answer 1

Here is the concept. You do the math.

First write the balanced equation

4Fe + 3O2 === 2Fe2O3

Next covert the grams of iron and grams of oxygen to moles, by dividing by the respective molecular mass.

Next use the molar stoichiometric ratio of 4 moles of Fe for every 2 moles of iron rust and multiply by ht emoles of Fe you calculated. Now do the same for the Oxygen, using the ratio of 3 moles of O2 for every mole of rust. The smaller of the 2 answers is based on the limiting reactrant and is the answer to your question