Sciencemadness Discussion Board

Crystallization

Xnerd1963 - 19-1-2015 at 15:49

About me:

Im very sick right now with an auto immune condition that is incurable.
I got bored with watching tv so i decided to break out the beakers and do something that would occupy my mind for a while. I get a lot from You Tube but its not the best info at times. So here I am.

I have been tinkering around with making transition metals and purifying crystals

I have been having a hell of a time with chlorides. They seem much harder to crystalize and keep crystallized.

Is this typical? Sulfates seem to be much more eager to crystalize


I'm having an absolute nightmare trying to crystallize Zinc Chloride
I can slowly boil off the solution 50ml at a time. and wait a day to see if it will crystallize but it never does. than if finally turns into a thick syrup.

Each day I place the samples in rubbermaid containers with large dish of sodium hydroxide, but even that does not seem to help>

Iron 2 and 3 chloride was a bit easier but still not great.


Any advice on techniques that may help me?

Thank you in advance

Molecular Manipulations - 19-1-2015 at 16:28

Zinc chloride is a nightmare to crystallize. It's the most soluble compound I know of, 614 grams/100 mLs at boiling to 342 at freezing. If you boil the solution until you see the first crystals forming, and then cool it you might get something, but don't count on it. I'm not sure if this is what you where doing, but if not give it a try.
Copper (II) chloride dihydrate is much easier, use the same "boil until crystals appear and then cool down" method. If you don't have any, it can be made from copper, hydrochloric acid and hydrogen peroxide.
Nice job with iron chloride, how'd you crystallize iron (II) chloride? It's very prone oxidation from dissolved oxygen. Also keep in in an airtight vial or it'll oxidize in crystal form as well.
Potassium nitrate is really fun and easy to crystallize.
Sucks that you're sick man, I haven't taken a single step all year, broke my ankle.

Chemosynthesis - 19-1-2015 at 16:34

I'm not sure about the predictability with simple ionic compounds, but drug formulations can vary in solubility, storage, and absorption characteristics by altering the salt anion.

As for crystallizing, try cooling the reduced volume/higher concentration zinc chloride solution (since zinc chloride's water solubility is proportional with temperature).

Xnerd1963 - 19-1-2015 at 17:51

iron II was easy, it just takes a long time
trick is to heat it slow and allow it to evaporate a little at a time covering it and let it sit for a day at a time.

it seems to want to shift to iron iii if you push it too fast.

Had sort of a hard time with iron sulfate as well. it wants to fall out as particles if you push too much heat.

copper seems to be pretty willing to crystalize. nitrate was more finicky but i seem to have that down now.

copper chlorides are tougher but doable.

im having a lot of fun tinkering.
i am lucky that i was in biotech for so long, i have a lot of lab crap to play with, just now found some recirculating pumps and a peristaltic pump as well.

last month i found 3 jun-air vacuum pumps that i had forgotten about sold 2 on ebay

sorry about you ankle.


im out of it, ill write more tomorrow
meds are kicking my ass

Quote: Originally posted by Molecular Manipulations  
Zinc chloride is a nightmare to crystallize. It's the most soluble compound I know of, 614 grams/100 mLs at boiling to 342 at freezing. If you boil the solution until you see the first crystals forming, and then cool it you might get something, but don't count on it. I'm not sure if this is what you where doing, but if not give it a try.
Copper (II) chloride dihydrate is much easier, use the same "boil until crystals appear and then cool down" method. If you don't have any, it can be made from copper, hydrochloric acid and hydrogen peroxide.
Nice job with iron chloride, how'd you crystallize iron (II) chloride? It's very prone oxidation from dissolved oxygen. Also keep in in an airtight vial or it'll oxidize in crystal form as well.
Potassium nitrate is really fun and easy to crystallize.
Sucks that you're sick man, I haven't taken a single step all year, broke my ankle.