PYRIDINEyade
Harmless
Posts: 11
Registered: 15-12-2022
Location: Japan
Member Is Offline
|
|
Unexplained crystals produced in the synthesis of potassium trisoxalatoferrate(III)
Greetings,
I recently synthesized potassium trisoxalatoferrate(III) by reacting an aqueous oxalic acid solution with potassium hydroxide and adding an aqueous
iron(III) chloride solution to it.
Then, a very small portion of the crystals had a blue-green color. What is this?
I have synthesized potassium trisoxalatoferrate(III) many times, but this is the first time I have seen it.
Regards,
|
|
PYRIDINEyade
Harmless
Posts: 11
Registered: 15-12-2022
Location: Japan
Member Is Offline
|
|
Always, as you can see in this picture, all the crystals are yellow-green.
|
|
Texium
Administrator
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 4552
Registered: 11-1-2014
Location: Salt Lake City
Member Is Offline
Mood: PhD candidate!
|
|
What was your source of iron(III) chloride, and was it the same stuff you used the previous times? If not, perhaps this time it was contaminated with
another metal like copper or nickel.
|
|
clearly_not_atara
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 2731
Registered: 3-11-2013
Member Is Offline
Mood: Big
|
|
Trisoxalatochromate is reportedly very dark blue.
|
|
PYRIDINEyade
Harmless
Posts: 11
Registered: 15-12-2022
Location: Japan
Member Is Offline
|
|
@Texium
As a source of iron(III) chloride, I used a etching liquid. I used the same etching liquid before.
https://www.amazon.co.jp/dp/B0020VFJ8K
After I started this thread, I asked my friend and he said that isotopes are the most likely source. Other possibilities are the crystal grains are
finer and thus appear optically bluish, or that some Fe(+3) may be reduced to Fe(+2) since oxalic acid is a reducing agent.
|
|
SnailsAttack
Hazard to Others
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 165
Registered: 7-2-2022
Location: The bottom of Lake Ontario
Member Is Offline
|
|
I don't
think that's a thing
|
|
violet sin
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1477
Registered: 2-9-2012
Location: Daydreaming of uraninite...
Member Is Offline
Mood: Good
|
|
Straight, fresh, clean etchant? Or, could it possibly have copper in there? Seems to me an impurity of some sort is the likely cause. Good luck.
Side note, I agree with SnailsAttack.
I doubt any kind of isotopic discrepancy would alter the color perceptibly, if at all. Pure gess, not looked into.
|
|