Suzanne E. answered • 10/23/21
How many litres of CO are required to react with 163.00g of iron(III) oxide?
First, you need the reaction:
Fe2O3 + 3CO → 2Fe + 3CO2
In order to solve this:
- convert weight of Fe2O3 to moles
- figure out how many moles of CO are needed to react with the number of moles of Fe2O3 given
- convert moles of CO to liters of CO
Step 1
(a) molecular weight of Fe2O3
= 2 x (atomic weight of iron) + 3 x (atomic weight of oxygen)
= 2 x 55.845 + 3 x 15.999
= 159.69
(b) moles of Fe2O3
= (163.00 g) / (159.69 g / mol)
= 1.02 mol
Step 2
The stoichiometric relationship is shown in the balanced equation at top.
You need 3 moles of CO for each mole of Fe2O3 you wish to react.
moles CO needed = 3 x moles Fe2O3 = 3 x 1.02 moles = 3.06 moles
Step 3
One mole of gas occupies 22.4 liters at standard temperature and pressure (STP). You are not given the temperature and pressure conditions for the gas, so we must assume STP.
liters of CO required for reaction
= mol of CO needed x 22.4 liters / mol
= 3.06 mol x 22.4 liters / mol
= 68.54 liters CO
J.R. S.
10/24/21
Suzanne E.
Step 1 (using five sig figs in the answer) > 163.00 / 159.69 g = 1.0207 (rounded to 1.02 in the initial solution)10/24/21
Suzanne E.
Step 2 (using new value) > 1.0207 * 3 = 3.062110/24/21
Suzanne E.
Step 3a (using 22.4) > 3.0621 * 22.4 = 68.59110/24/21
Suzanne E.
Step 3b (using 22.402) > 3.0621 * 22.402 = 68.59910/24/21
Suzanne E.
If you round the results from 3a and 3b to four sig figs, you get 68.59 (3a) and 68.60 (3b) - and 68.59 is the desired answer. So not only must you assume that the CO is at STP, you must also assume that you are using 22.4 as the value for liters per mol CO. You must additionally assume that 22.4 is a constant and hence infinitely precise. So here is a question for your teacher: why is the desired answer in four sig figs and not five?10/24/21
Christopher E.
So with the questions here, my teacher included the answers (68.59) and we just have to show the work. how is your answer 68.54?10/23/21