In the production of iron one of the steps involves the reaction of iron (III) oxide with carbon monoxide. The products of this reaction are carbon dioxide and iron (II,III) oxide (Fe3O4(s)). Calculate the standard molar heat of reaction for iron (III) oxide using Hess's mathematical approach.
So I've worked out:
3 Fe2O3 (s) + 1 CO(g) -> 1 CO2(g) + 2 Fe3O4(s) Which I think is correct.
∆rH = [n∆fHmCO2 + n∆fHMFe3O4 ] - [n∆fHmCO + n∆fHmFe2O3 ]
So then I do not know what to do. In the end I want to find n∆fHmFe2O3 so what would my approach be? Please help.
So I've worked out:
3 Fe2O3 (s) + 1 CO(g) -> 1 CO2(g) + 2 Fe3O4(s) Which I think is correct.
∆rH = [n∆fHmCO2 + n∆fHMFe3O4 ] - [n∆fHmCO + n∆fHmFe2O3 ]
So then I do not know what to do. In the end I want to find n∆fHmFe2O3 so what would my approach be? Please help.
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Your setup is exactly right. There is something wrong with the question ... because if you were looking for the molar enthalpy of Fe2O3, you would need the enthalpy of the entire reaction. Since you don't have that (and since the molar enthalpy of Fe2O3 is in your data booklet) we must assume you're looking for the molar heat of reaction of the entire equation .... and to find that, you simply sub in numbers into your equation and you end up with -47.2 KJ. i suppose you could then divide this by 3, which gives you -15.73 KJ/mol of Fe2O3.
thats really the only possible way to do this question, but it seems as if something is missing because while this gives you a mathematical answer - it is (in real life) extremely incorrect. but maybe its just judging your knowledge of the Hess's Law concept.
Anyways, I hope this provides you with a bit of clarity. Good luck!!
thats really the only possible way to do this question, but it seems as if something is missing because while this gives you a mathematical answer - it is (in real life) extremely incorrect. but maybe its just judging your knowledge of the Hess's Law concept.
Anyways, I hope this provides you with a bit of clarity. Good luck!!