Review worksheet week 1: question 9 [ENDORSED]

[Husnia Safi - 1K]

What mass of CO is required to react completely with 25.13 g of Fe2O3 according to the equation:
Fe2O3 + 3CO ----> 2Fe + 3CO2

[Liliana Rosales 1E]

You would start by converting 25.13g of Fe2O3 into moles, which is done by dividing the grams given by the molar mass of the Fe2O3. Then you would look at the chemical equation given and see how many moles of Fe2O3 there is for every mole of CO. In this case, for one mole of Fe2O3, there is 3 moles of CO. After figuring out this ratio, you would convert the moles of CO into grams to get the final mass. Hope this helps.

25.13g of Fe2O3 x 1 mol of Fe2O3/159.69g of Fe2O3x 3 mol of CO/1 mol of Fe2O3 x 28.01g of CO/1 mol of CO = 13.22g of CO

[Caitlyn Ponce 1L]

As a side note, always make sure that the equation is balanced. In this problem, the given chemical equation is already balanced, but for future exercises, check in case so you can have the correct stoichiometric ratios :)

[Alicia Beebe]

What I did was converted the 25.13 g of Fe2O3 into moles by dividing by its molar mass (159.69) to get that .157 moles of Fe2O3 were consumed. When looking at the stoichiometric coefficients, we can see that for every 1 mole of Fe2O3, there needs to be 3 moles of CO. Thus I multiplied the .157 moles (needed of Fe2O3) by 3 to get that .472 moles of CO are needed. Lastly, I multiplies the .472 moles by the molar mass of CO (28.01) to get that 13.22 grams of CO are needed.

[Liliana Rosales 1E]

Thank you for sharing, your method sounds easier and quicker compared to mine.