extraction of iron on a match head

[Moogie]

Hi

Please look at this link. It is only very brief. It describes how to extract iron from iron oxide on a match head.

My questions are:

where does the carbon come from in this equation

Iron(III) oxide + carbon → iron + carbon dioxide

2Fe2O3(s) + 3C(s) → 4Fe(s) + 3CO2(g)


Is it from the wood in the match?

Why sodium carbonate is needed? The page says:
The sodium carbonate fuses easily and brings the iron oxide into close contact with the carbon.

I dont really know what that means

thanks

[Borek]

No link to look at.

[Moogie]

sorry
http://www.practicalchemistry.org/experiments/introductory/change/extraction-of-iron-on-a-match-head,99,EX.html

[lightarrow]

My questions are:
where does the carbon come from in this equation
Iron(III) oxide + carbon → iron + carbon dioxide

2Fe2O3(s) + 3C(s) → 4Fe(s) + 3CO2(g)

Is it from the wood in the match?It seems so, it says to make the match burn to about half lenght.


Why sodium carbonate is needed? The page says:
The sodium carbonate fuses easily and brings the iron oxide into close contact with the carbon.
I dont really know what that means
IMO it means that sodium carbonate melts and so mixes iron oxide within the liquid phase, this shoud make the solid particles of oxide penetrate inside the carbon increasing the area of contact.

[chemisttree]

The carbon is added as an ingredient in the red part of the match. It can be present as carbon black and as a binder. The binders can be (but aren't necessarily limited to) gelatin or starch, both of which can be sources of carbon. Most match sticks (not the heads) are impregnated with paraffin which can volatilize and be a source of carbon as well. Of course there is the wood or paper substrate as well.

[Moogie]

Sorry, I still don't understand why sodium carbonate is needed, thanks

[chemisttree]

I believe the match stick's head is just moistened a bit and rolled in some iron oxide followed by the sodium carbonate. If you have ever watched a match burst into flame you might expect a powder on its surface to be launched off into space! The sodium carbonate melts and keeps it put until the flame front reaches it and some chemistry has a chance to happen. Think of the sodium carbonate as this reaction's post it note... STAY THERE UNTIL I CAN DEAL WITH YOU.

[Moogie]

Thank you.