Lion850
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Report on making Iron Iodide
1) 50ml water in 100ml beaker on hot plate stirrer
2) Add 3g iron filings. Immediately had a problem (should have remembered) because the filings stuck to the stir bar. Tried only the filings but they
did not move. Decided to proceed with the filings stuck to the stir bar.
3) Add 2g iodine, purple color, heat, after 5 minutes a dark solution with yellow splashes on the beaker sides.
4) After total 10mins added 2g I2 to the near boiling solution, purple color for a few minutes before just dark again. Some I2 vapour boiling out for
maybe 30 seconds, switch off heat.
5) At 20min mark added 1.5g I2, at 25min mark added 2.5g I2.
6) At 35min bring to boil, no I2 fumes, add 2g I2. Top up water to 50ml mark.
7) At 45min add 2g I2, total added now 12g.
8) 60min mark: stop boiling. No sign of I2 fumes or purple in solution. Water had been allowed to boil down to around 20ml mark.
9) Filter hot. Obtain a green solution (see photo 1). Still some what appears to be iron filings on the stir bar, so not all iron was consumed.
10) Very small amount of black sludge on filter paper, discarded.
11) Transfer green filtrate to watch glass and place on boiling beaker. As the liquid heated up it became more yellow and eventually red-brown.
12) On boiling beaker for 2 hours. Some dark crust forming, stop for the night.
13) Next day some of the crust disappeared. Boil for another 3 hours. Crust with fluid layer underneath. Remove watch glass from beaker as I was
suspecting the heat was causing the iron iodide to melt in its crystal water.
14) As it cooled it solidified to a very hard layer (photo 2). Broke it up with brute force and transfer to vial: total recovery 9.6 gram. Shows
crystal structure on the flat plates.
15) Noticed the small pieces that remained on the watch glass very quickly became wet. Yellow color when a thin wet layer, more red when wetter. Photo
3.
16) Dissolved a small piece of the solid in water, obtained a red solution. Test with a grain of Lead Nitrate, obtained yellow Lead Iodide ppt. Photo
4.
I'm pretty sure this is Iron (ii) Iodide, FeI2. Not sure what yield I achieved as the final product for sure has an unknown water of hydration
content.
Seems the color of FeI2 depends a lot on how it was made. According to "A Comprehensive Treatise on Inorganic and Theoretical Chemistry: volume 13”
in the Sciencemadness library reports as below (and there are more) that seems more or less in line with my observations:
- obtained a steel-grey, laminated mass of ferrous iodide.
- concentrated solution is green
- forms plate-like crystals of a deep red colour with a brownish tint; in thicker masses the colour of ferrous iodide is nearly black.
- When melted and allowed to solidify, it forms a reddish-black crystalline mass with a brown tinge on the fractured surface.
- the crystals are black in reflected, and garnet-red in transmitted light.
Not sure which iodide to try next. Today I got a desiccator, so I can revisit some previous iodides that I could not dry properly. Like the Aluminium
iodide that I got concentrated enough to fume in air (see the last addition to my previous report) but I could not get as dry crystals.
    
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woelen
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Interesting synthesis. I learned about colors of many iodide compounds. I did not know that iron(II) iodide is black, always thought it to be green.
You could try making anhydrous CoI2. You need very fine cobalt powder for that though.
Another one may be PI3. Not that difficult to make if you have powdered red P. It is air-sensitive though, it hydrolyses in contact with humid air.
BiI3 also is interesting to make. It can even be made from aqueous solution (it is black). When dissolved in excess iodide, you get a deep orange
solution, like a very concentrated solution of K2Cr2O7. Worth a try if you have bismuth oxide or basic bismuth nitrate, dissolved in dilute HNO3 or
dilute H2SO4. On partial hydrolysis you also can get the brick-red BiOI (not an hypoiodide, but a mixed oxide/iodide, with bismuth in +3 oxidation
state). Not that easy to make, you easily get overhydrolysis tot white hydrous Bi2O3, or underhydrolysis with an impure mix of BiOI and BiI3.
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Tsjerk
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Is there a legal amount of P to own in Australia? I can send you some for shipping costs but I also know Australian laws can be a pain...
Edit: This offer is only for Lion850, or for other people that make nice reports like Lion850 does.
[Edited on 23-12-2019 by Tsjerk]
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Lion850
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Woelen - I want to make more FeI2 and then dry the lovely green solution in my desiccator and see what I end up with. There are reports of dark green
crystals.
Don't have Cobalt powder yet.
I do have Bismuth and will get around to that one.
Still waiting for my titanium powder to arrive to have another go.
Tsjerk - thanks for the great offer! I am indeed struggling to get my hands on some red P down here. I do not think it is illegal to own, as long as
it is not used to make something illegal. Happy to pay for shipping.
I sometimes wonder if I put too much detail into my reports but the idea is that members with more experience can tell me where I go wrong or where
things could be done different or better.
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draculic acid69
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Until u start adding things like made cup of tea with 2sugars in-between step 3 and step4 and went to the bathroom shook it twice zipped back up
started step6 your not adding too many details.this a detail oriented subject and too few details can be a problem.too many isn't really an issue.
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