In order to answer this question, you first need to know the molar mass of the Fe_{2}O_{3}. You can calculate this by adding up the atomic masses of each of the atoms in the molecule. So for instance, Fe has an atomic mass of 55.847 amu/mol. Since there are two Fe atoms in each molecule of Fe_{2}O_{3}, we need to add 55.847 amu/mol *twice*. We then add one atom of C (atomic mass 12.001 amu/mol) and three atoms of O (atomic mass 15.999 amu/mol) which gives us a total molecular mass (since were talking about a molecule now, not atoms) of 159.69 amu/mol. This also means that 159.69g of Fe_{2}O_{3} is equal to one mole of Fe_{2}O_{3}.

Now that we have the molar mass of Fe_{2}O_{3}, we have to determine how many moles of Fe_{2}O_{3} we have. We do this by dividing the given mass of Fe_{2}O_{3} by the molar mass we found in the first part, above. Once we divide 2829g Fe_{2}O_{3 }by 159.69 g/mol Fe_{2}O_{3}, we find that we have 17.716mol of Fe_{2}O_{3}.

Now we need to really look at the chemical reaction. More specifically, we need to look at the coefficients in front of each of the reactants and products. Those coefficients tell us how much of each reactant is needed in order to produce an amount of product. In this problem, there is no coefficient in front of Fe_{2}O_{3}, so we can assume its coefficient is 1. The 2 in front of Fe tells us that every time this reaction is run, 2 moles of Fe will be produced. SO... for every 1 mole of Fe_{2}O_{3} we put into the reaction, 2 moles of Fe will be produced.

If we put 17.716 mol of Fe_{2}O_{3}, which we found above, all we need to do is double that number to get our final answer: 35.52 mol Fe.

Mikal T.

In situation above you actually obtained 1657g of Fe. What is the percentage yield?06/23/21

Brian C.

06/23/21

Christian K.

Brian did a great job explaining this problem, but he left out the very last step. Since the question asks us to calculate the number of grams of iron, we need to convert the moles of Fe to grams using the molar mass of iron. As previously stated, every mole of Fe has a mass of 55.847 g (from the periodic table). Thus: 35.52 mol Fe x 55.847 g/mol = 1947 g (4 sig figs)06/23/21