[albgk]

Being a citezen chemist, I like to make my chemicals myself rather than ordering them. I recently went out and got the product Root Endz (having Copper Sulfate and other inert materials). I left it out to evaporate, and yesterday I noticed Copper Sulfate crystals forming but it still had some solution left... today i noticed that it had all dried up and there was a white powdery substance on it. So i was wondering what the substance was and how i could seperate the powder from the copper sulfate..

thanks

albgk

[billnotgatez]

does this help

http://www.roebic.com/pdf/rootendzMSDS.pdf

[albgk]

hey thanks bill that does help... but that doesn't explain the white powder that has formed... can anyone explain this???

p.s. srry for the lateresponse i have been out of town

[Kitchench3m]

Well its relatively safe to assume that the blue crystals are in fact the CuSO4 that you are looking for. I know that the anhydrous form of CuSO4 is a white powder like substance, but if you weren't vigorously heating the solution they most likely would not have formed. I would try manually removing the powder and attempting to recrystalize the stuff. If blue crystals form then great. If not it's most likely some of the left over inert ingredient. Depending on the purity of the substance you need, you could redissolve the blue crystals and reform them again. Then remove the powder if any remains, and repeat until you get the desired big bright shiney crystals you need . (on a side note... don't lick the stuff, tried it as a kid not too great)

[Borek]

Mechanically remowing white powder is not a good idea. Just don't let it dry completely and filtrate copper sulfate BEFORE white crystals start to form.

http://en.wikipedia.org/wiki/Recrystallization

[Archenar10]

Mechanically remowing white powder is not a good idea. Just don't let it dry completely and filtrate copper sulfate BEFORE white crystals start to form.

http://en.wikipedia.org/wiki/Recrystallization

If you extract the solution and recrystlize, you will still be getting CuSO4 crystals from the CuSo4 that were in solution. So it will make it more difficult to determine if the white powder was CuSO4 in other form.

But why is it not a good idea to remove them mechanically?

By doing so, you completely separate the white powder from the CuSO4 crystals. So if CuSO4 blue crystals form again, then you know it was just another form of CuSO4 and not other residue.

[Borek]

White powder was not other form of the copper sulfate.

Allowing mixture to dry completely you force growth of contaminated crystals. This way you will never get pure copper sulfate.

[Fleaker]

Perhaps salt is added to it? Basic copper carbonate can also form (this is bluish white as I recall)...