I used copper(ii) sulfate with sodium bicarbonate to create copper carbonate. I ran the non-soluable copper carbonate through a filter and rinsed it
with water to get rid of most of the sodium. After this I let it dry, then crushed it up and let it dry even more to prepare it for the second
filtering and crystallization to further purify the copper carbonate.
However when I went downstairs to examine it the next morning, I found this white candy floss textured substance growing from the pestle. I'm
assuming it's the sodium contaminate, but it's rather intriguing to look at and see the next morning. Can someone explain a bit more of what's going
on here?
And no, I don't practice chemistry in my kitchen. I took it up there to take a picture with the sunlight.
[Edited on 16-4-2013 by binaryclock]blogfast25 - 16-4-2013 at 09:00
Could it be sodium sulphate, from incomplete washing of your copper carbonate? It would be worth collecting some of the substance, dissolving it in
water and testing that solution for sulphates with Ba nitrate or chloride. Or calcium but calcium sulphate does have some limited solubility.
[Edited on 16-4-2013 by blogfast25]watson.fawkes - 16-4-2013 at 09:22
It looks to me like a form of efflorescence, with an intriguing habit that forms that foamy shape. If I had to guess, I'd say that the copper
carbonate is adsorbing onto the surface of the crystal in a way that promotes tip growth preferentially. After a bit of this, water will
preferentially evaporate from near the "surface" of the foam puff, leading to a very low density habit. Just a guess.
I'd love to see some microscope images of it, to see if they really are filamentous crystals in there.binaryclock - 16-4-2013 at 09:40
Thanks for the replies. It is important to also note that when this formula was in the evaporation dish, the floss (crystals?) did not form. Only
when it was on the mortar and pestle did the floss form, also in less than about 6 hours.
Here is a youtube video that I took as well . It may give a bit more detail. The heavy breathing is my mask.. just ignore that.
[Edited on 16-4-2013 by binaryclock]Fantasma4500 - 16-4-2013 at 11:02
MASK?? oh wait, i will do as you say and ignore the heavy breathing through the .. mask..
i have often been wondering about these very strange crystal growths...
fx. i have some AN solution being dessicated in a plastic container inside another container where the bottom is covered with anh. CaCl2..
i found it later that the CaCl2 made itself into HUGE chunks and it started crawling up the plastic container
very long and nice needle crystals in the plastic container, but the inside of this container was covered with crystals seeming of another texture
climbing up the containers walls and covering it all..
found out that it was luckily not contaminated with CaCl2, but rather both substances crystallized on the container..
im not sure what to think about this.. like its all alive when put in darkness
but by the chemical equation
CuSO4 + Na2CO3 > CuCO3*2Cu(OH)2 + Na2SO4
i would say it cant be much more than Na2SO4, perhaps Na2CO3, but if you used correct stoichiometry its unlikely..woelen - 16-4-2013 at 22:47
No need to use a mask with this type of experiments It's not phosgene you are
working with, it's just copper sulfate!
The pestle you are working in, does it have a clean and smooth ceramic surface, or is it rough and unpainted? In the latter case there might be
soluble matter coming out of the porous ceramic material it is made of.
Another explanation may be the presence of a lot of sodium ions in your product. It is well-known that in precipitation reactions other ions
coprecipitate and that these ions may be amazingly hard to remove, especially if the precipitate is flocculent or slimy. Such flocculent or slimy
precipitates are formed if the resulting compound is highly insoluble and the precipitate forms at once. If the precipitate is created more slowly
(e.g. when solutions of NaIO4 and KCl are mixed, then KIO4 slowly precipitates), then it is much more compact and consists of fine crystals. Such
precipitates are more pure.
blogfast25 - 17-4-2013 at 05:11
Precipitation from concentrated solutions promotes occlusion of salts. After washing and drying I've seen copper carbonate develop a rim of white,
salty matter. This encrustation may be similar to what binaryclock may be seeing. Although why precisely it ends up on the pestle remains to be seen.
[Edited on 17-4-2013 by blogfast25]binaryclock - 17-4-2013 at 06:20
Thanks for all the information. I appreciate it! The end of the pestle is unfinished and rough so it is porous.
As far as the mask... I seem to get headaches and phlegm when working with airborne copper dust. I don't use a mask when I'm filtering it or anything
and when it's wet. I didn't wear any gas mask for a few days, but after getting headaches and soar throats after working with the dust, I figured I'm
going to get serious and start wearing protection. Copper sulfate and carbonate is a mild irritant from what I read and some people are more
sensitive than others. My skin is never effected by the copper when it touches me.. just my respiratory system.
Even in my woodworking hobby, airborne sawdust really effects me so I have to wear a dust mask when working with power tools and wood. My ears will
start to ring, I'll get headaches and everything.
[Edited on 17-4-2013 by binaryclock]watson.fawkes - 17-4-2013 at 10:02
Even in my woodworking hobby, airborne sawdust really effects me so I have to wear a dust mask when working with power tools and wood. My ears will
start to ring, I'll get headaches and everything.
Sounds as if you've had lots of accumulated exposure to
allergic sensitizers. They don't have to cause an allergic reaction themselves in order to sensitize you to future exposures. I'd also guess this is
the origin of your sensitivity to copper salt dust, to which many people don't have a reaction.
It's not phosgene you are
working with, it's just copper sulfate!