Hello all, it's been a while! (busy with school and things, you know)

Anyways, I've got an itch to get my hands on some CoCl2. It's a very cool chemical. It is strongly hygroscopic, going from CoCl2 anhydrous to CoCl2*6H20 in the presence of air. The anhydrous form is blue, and the hexahydrate is a deep red! It's used in those silica gel pellets that indicate when they need to be dried again.

It also can be used (and this is why I want it) as an invisible ink that appears when heated, then disappears again as the CoCl2 becomes hexahydrate again. This reaction can be done over and over with the same secret message.

However, a quick gander on ebay will confirm that it is pretty expensive! My local ceramics shop has a few cobalt compounds for sale. The first that caught my interest is CoCO3, which I know I can react with HCl, but the CoCO3 is also very expensive. I can get CoSO4 for much cheaper, but will this react with HCl?

I might be able to buy a very small amount of CoCO3 from the pottery shop if I can convince them to sell me a smaller amount than they offer (usually the minimum size offered is 1/2 pound bags, which is WAY more than I need). So that would make my life easy. But if they won't...Can I react CoSO4 with HCl? Or can I do some other roundabout reaction with it to end up with CoCl2?

If I am successful in acquiring CoCl2, I will definitely post pictures of its very interesting properties!

http://www.sciencelab.com/page/S/PVAR/10410/SLC1468?gclid=CKv3k6K-m5cCFRlRagodpD9H-A

that should do it ?

vailable Quantities/Sizes
SKU Size Price Quantity
SLC1468-25G 25 g $40.64

I don't have that kind of money!

I don't have that kind of money!

thats to fucking bad bro take parents/grandparents/friends parents credit card

Or....I could be a mature, resourceful individual and react the cheaper compounds with hydrochloric acid to get what I want. Assuming that the reaction I proposed is a viable reaction. Which is what I am asking.

I have maybe 100-200g of cobalt sulfate I got off ebay in a lot of other ceramic chems... Total price was probably about $40... So you might just watch ebay like a hawk though I got pretty lucky.

I have been wanting to do this myself for a long time but havn't got around to it. If you can remind me about this closer to xmas when I have free time I'll help you out more with research and testing if you don't figure out something before then on your own. Just pop in the IRC room and get one of the guys to change the topic notifying me or post something about it in the PRRT or something. I was considering going:

CaCl2 + CoSO4 ---> CaSO4 + CoCl2

Letting the sludge of calcium sulfate fall to the bottom and then carefully siphon off the cobalt sulfate solution being careful not to get too much of the calcium sulfate in it. Barium chloride would be another possibility as barium sulfate has an extremely low solubility, but then your messing with even more poisonous things, so meh.

But yeah if you do any testing just make sure you do it very small scale so that if it doesn't work its not a waste.

My inspiration for it is this:
"We use cobalt (II) chloride in a saturated sodium chloride solution to
demonstrate cooling coils. It changes from red/pink to a blue/purple when
heated and reverses as it is cooled. We cycle it through a condenser from
a distillation to illustrate that portion of a simple set-up."

I can't remember where I found that quote, but there ya go. If you got the flow rate and temps just right it could look awesome in a watercooled computer or as re-circulating coolant for distilling things... The major problem I see when using it for computers though is that the solution conducts electricity, so if you spill some on the mobo, your fucked much more so than if you spilled distilled de-ionized water. Or atleast thats what I assume.