cnidocyte
Hazard to Others
Posts: 214
Registered: 7-7-2010
Member Is Offline
Mood: No Mood
|
|
Reacting steel wool with H2SO4
I added some concentrated H2SO4 to some fine steel wool, the objective being to synthesise some Fe(II)SO4. The reaction started instantly and made a
sizzling sound. I'm not too sure what SO2 smells like but I could definitely smell some H2S. The product was a greyish white foam (there was lots of
unreacted stuff left over from the steel wool so its hard to say what the product actually looked like).
I read up on this reaction before I tried it but there was a lot of conflicting claims. Some sites claimed Fe2O3 is the product, some claimed its FeO
while others claimed its FeSO4. There was no red product so I definitely didn't make any Fe2O3 and considering H2S was a product, not all, if any of
the iron was converted to iron (II) sulphate. This would be my guess
3Fe + H2SO4 -> Fe3O4 + H2S
but this stuff wasn't black.
|
|
|
hkparker
National Hazard
Posts: 601
Registered: 15-10-2010
Location: California, United States
Member Is Offline
Mood: No Mood
|
|
If it wasnt black its not Iron(II,III) Oxide, but thats weird, not sure what it would be. FeO is black too. Anyway this should be posted in general
chemistry, not reagent and apparatus acquisition, repost it there.
My YouTube Channel
"Nothing is too wonderful to be true if it be consistent with the laws of nature." -Michael Faraday
|
|
|
Jor
National Hazard
Posts: 950
Registered: 21-11-2007
Member Is Offline
Mood: No Mood
|
|
Yuou have a solution of FeSO4, and maybe some Fe(III) formed too, because conc. H2SO4 is a decent oxidiser.
The black material is carbon, wich is present in steel.
|
|
|
cyanureeves
National Hazard
Posts: 737
Registered: 29-8-2010
Location: Mars
Member Is Offline
Mood: No Mood
|
|
I made a bunch of ferrous something with steel wool and sulfuric acid too,but when i add it to potassium cyanate it turns orange.I think it may have
some salt added for cleaning purposes.This really pissed me off as I added this crap to my other sulfate I had made with sulfuric acid and ordinary
steel plate.My first batch made the prussian blue color immediately upon contact.I still get the prussian blue pigment but not until i add ordinary
bleach.I found this out when I went to decompose it with sodium hypochlorite before discarding.
|
|
|
ScienceSquirrel
International Hazard
Posts: 1863
Registered: 18-6-2008
Location: Brittany
Member Is Offline
Mood: Dogs are pets but cats are little furry humans with four feet and self determination! 
|
|
It is quite easy to make ferrous sulphate from steel wool but it is important to remember two things. You must have a slight excess of acid and steel
wool present in the solution at all times and handle without exposing to the air as much as possible to avoid oxidation and It has several hydrates.
The hydrates are generally blue green and green but the monohydrate is whitish grey. Depending on concentration and temperature the various forms will
crystallise.
Have a look at the solubility table here; http://en.wikipedia.org/wiki/Solubility_table#I
To get nice crystals of the blue green heptahydrate is a test of skill and some ability to calculate!
|
|
|
smaerd
International Hazard
Posts: 1262
Registered: 23-1-2010
Member Is Offline
Mood: hmm...
|
|
So I just had a lovely mint green solution of FeSO4 then I got all excited and started to distill some excess water off, and yucky the oxidized
product formed no mint-green remaining. I filtered it and the solution is significantly less mint-green but no more oxidized product is visible.
Wish I would have known about this oxidized product before!
|
|
|
Wizzard
Hazard to Others
Posts: 337
Registered: 22-3-2010
Member Is Offline
Mood: No Mood
|
|
I have some wonderful crystals of ferrous sulfate- Anybody want some pictures?
And I agree- The minty crystals sure are lovely, it's very sad they don't like the fresh air I had a large batch I put in a small ziplock... And forgot to lock the zip :C
|
|
|
smaerd
International Hazard
Posts: 1262
Registered: 23-1-2010
Member Is Offline
Mood: hmm...
|
|
Pictures would be awesome!
I initially thought this would be a cake-walk preparation. Added some H2SO4 to some steel wool thought that would be the end of it hehe. Now I'm
concentrating it by adding more H2SO4 and much more steel wool.
It was weird as soon as I added more conc h2so4 to a dilute solution it turned pink until I added more steel wool. Now it's happily emitting H2S(I
think) on the patio hehe.
Because I bumped an old thread I guess it is best to add something to it. So here's a procedure if anyone get's the old UTFSE in the future - http://www.crscientific.com/ferroussulfate.html.
|
|
|
smaerd
International Hazard
Posts: 1262
Registered: 23-1-2010
Member Is Offline
Mood: hmm...
|
|
I had beautiful crystals but I had to break them down to get them out of the erlenmeyer, anyhow here's the final product of this 
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
