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Chemistry Forums for Students => Inorganic Chemistry Forum => Topic started by: rickyponting66 on April 25, 2011, 04:53:23 PM

Title: Which substance cannot reduce iron (III) oxide to iron?
Post by: rickyponting66 on April 25, 2011, 04:53:23 PM

Which substance cannot reduce iron (III) oxide to iron?
a) Carbon dioxide
b) Carbon monoxide
c) Coke (carbon)
d) Hydrogen

Title: Re: Which substance cannot reduce iron (III) oxide to iron?
Post by: SirRoderick on April 25, 2011, 05:25:56 PM

Kind of odd you would post a multiple choice question, but hey.

Carbon, Carbon monoxide and Hydrogen I believe can reduce Iron(III) to Iron. So then the awnser would be CO₂. I'm not looking at the tables right now, but if memory serves that should be correct.

Title: Re: Which substance cannot reduce iron (III) oxide to iron?
Post by: DevaDevil on April 26, 2011, 05:07:15 PM

a substance which can reduce iron (III) has to be oxidized itself of course. So this question can also be read as: which compound can be oxidised?

you will see that carbon dioxide has carbon in its fully-oxidised 4+ state and cannot oxidise further, therefore it cannot reduce iron (III)

Title: Re: Which substance cannot reduce iron (III) oxide to iron?
Post by: SirRoderick on April 26, 2011, 06:30:53 PM

Quote from: DevaDevil on April 26, 2011, 05:07:15 PM

a substance which can reduce iron (III) has to be oxidized itself of course. So this question can also be read as: which compound can be oxidised?

you will see that carbon dioxide has carbon in its fully-oxidised 4+ state and cannot oxidise further, therefore it cannot reduce iron (III)

Should have thought of that actually, good way to rule it out. Still, memory did serve!