I’m doing an online chem course and the textbook isn’t very good at explaining concepts.Calculating Mass of Reactants and Products:The Question is:1. Metallic iron can be obtained by heating iron ore, Fe2O3, with hydrogen. The balanced equation for the reaction id given below.Fe2O3 + 3 H2 2 Fe + 3 H20a) What mass of iron is produced from 500kg of iron ore?b) What mass of hydrogen gas is required to convert 1.0 t of iron ore into iron?c) If 220kg of water is formed, what mass of iron ore was used up?In the textbook there are three steps to calculate the mass of reactants and products.1. Convert the measured mass into moles2. Use the mole ratio in the balanced equation to predict the amount in moles of desired substance.3. Convert the predicted amount in moles into massThe only step I don’t understand is step 2 with mole ratioThe best answer would be the one that is the most clear, simple, and easy to understandThanks for the help
The mole ratio is the numbers out front of the molecules. In your example, one mole of Fe2O3 reacts with 3 moles of H2 generating 2 moles of Fe and 3 moles of H2O. So if you were to find that you converted x number of moles of Fe2O3, you would produce 2*x moles of Fe. This would also consume 3*x moles of H2 and produce 3*x moles of H2O. This relationship can be used in reverse as well. If we know that y moles of H2O were produced, then we must have converted 1/3*y moles of Fe2O3 into 2/3*y moles of Fe.
The mole ratio is the number in front of the compound. No number 1 ONE mole Fe2O3 produces TWO moles Fe 1:2 ratio THREE moles H2 produces THREE moles H2O 3:3 or 1:1 ratio And all other combinations. So, if you have X moles Fe2O3 you have 2X moles Fe produced. If your working from the other end of the reaction, the ratio is reversed. i.e. X moles Fe 1/2 moles ore. Hope this helps.it really makes sense when you write the problem out and include the mole ratio as part of your equation.
The first step is to understand what the balanced equation is telling you: Fe2O3 + 3H2 → 2Fe + 3H2O 1mol of Fe2O3 will react with 3 mol H2 to produce 2mol Fe and 3mol H2O Your q a): What mass of iron is produced from 500kg of iron ore? The Fe2O3 is the iron ore. Your text book tells you: 1. Convert the measured mass into moles So you need to know how many moles of Fe2O3 are in 500kg Fe2O3 You do this by calculating the molar mass of Fe2O3: you add up the respective atomic masses from the periodic table: Molar mass Fe2O3 Fe 55.847 Fe2 55.847*2 111.694 O 16.0 O3 16*3 48 Total 111.694+48 159.694g/mol Moles in 500kg 500,000g 500,000/159.694 3,130.988moles Fe2O3 Now go to the next instruction from your text book: 2) Use the mole ratio in the balanced equation to predict the amount in moles of desired substance. From the balanced equation you saw that 1mol Fe2O3 will produce 2 mol Fe. The mol ratio is 1:2 For every 1 mol of Fe2O3 you have, you will get 2 mol Fe You have calculated that you have 3,130.988 mol Fe2O3. So you must expect to get 2 X 3,130.988mol Fe 6,261.976 mol Fe Finally go to the last instruction from your text book: 3) Convert the predicted amount in moles into mass 1 mol of Fe will have mass 55.847g - as before this is from the periodic table and you used this mass above. Therefore 6,261.976mol will have mass: 6,261.976*55.847 349,712.575g Your question was worded as 500kg Fe2O3 - so you do not want to quote your answer in grams, change it to kg - divide by 1000 349.7 kg I would submit 350kg as answer. If you follow what I have done and the logic of your text book which has given you absolutely perfrect instructions, then you should have no problems with the other questions. But if you do email me.
