Question #9937f

2 Answers
Dec 21, 2014

The answer is 998 tonnes of Fe2O3 and 225 tonnes of C.

Since this is a multi-step reaction, we'll use the step

2C(s)+O2(g)2CO(g)

and the main chemical reaction

Fe2O3(s)+3CO(g)2Fe(l)+3CO2(g)

We know the mass of Fe produced, which is given to be 700.0106g (I've converted it to grams because it will be easier to work with), and Fe's molar mass - 55.8gmol - which means we can calculate the number of moles

nFe=mmolarmass=700.0106moles55.8gmol=1.25107 moles

Since we've got a 1:2 mole ratio between Fe2O3 and Fe, the number of moles of iron (III) oxide will be

nFe2O3=nFe2=6.25106 moles

Iron (III) oxide's molar mass is 59.6gmol, which means the mass of Fe2O3 needed is

mFe2O3=nmolarmass=6.25106159.6=998106g

Since we were dealing with tonnes, this is equal to 998 tonnes.

In order to determine the amount of coke (C) needed, we need to know how many moles of CO are required for the main reaction; since we have a 2:3 mole-to-mole ratio between Fe and CO,

1.25107molesFe3molesCO2molesFe=1.88107moles

Notice that we have a 1:1 mole-to-mole ratio for C and CO in the first reaction, so

nC=nCO=1.88107 moles

Therefore, the mass of C needed is

mC=nmolarmass=1.8810712.0=225106g

Again, converting to tonnes will get us 225 tonnes.

Here's a video detailing the process:

Dec 21, 2014

You will need 1001 t of iron(III) oxide and 226 t of coke.

The balanced equations are

Fe₂O₃ + 3CO → 2Fe + 3CO₂
2C + O₂ → 2CO₂

Iron(III) Oxide

You have to convert mass of Fe → moles of Fe → moles of Fe₂O₃ → mass of Fe₂O₃

We can do this in one long step.

700 t Fe×1000 kg Fe1 t Fe×1 kmol Fe55.845 kg Fe×1 kmol Fe2O32 kmol Fe×159.69 kg Fe2O31 mol Fe2O3×1 t Fe2O31000 kg Fe2O3=1001 t Fe2O3

Coke

Here, you have to convert mass of Fe → moles of Fe → moles of CO → moles of C → mass of C

700 t Fe×1000 kg Fe1 t Fe×1 kmol Fe55.845 kg Fe×3 kmol CO22 kmol Fe×2 kmol C2 kmol CO2×12.01 kg C1 kmol C×1 t C1000 kg C= 226 t C