[superg]

hi all,

we've got some cobalt chloride in the lab (hydrated, red-pink color) and i need some anhydrous for a synthesis. is there any way to dehydrate this compound, without heating it to extreme temperate?

cheers

[DrCMS]

an oven at 110°C

[superg]

thx

but i've read somewere that water in compounds can be hard to remove, heating them at 110° can't be enought...

bye

[DrCMS]

Why ask for advice if you then ignore it?

Go and Google the use of Cobalt chloride as indicator in silica gel drying granules.

I've dried them from pink to blue at 110°C in an oven but obviously as you've read something somewhere about something else that means I must be lying.  Why not put some in an oven and find out which one of us is right and then do your reaction either that or carry on whinging and get nowhere.

[superg]

the prep i have consist to react SOCl2 with the hydrated chloride salt...so why they use this quite harsh method if all the water goes off only at 110°? perhaps because they need extra dry cobalt chloride?

my initiial question was to know if it's the anhydrous compound that is made just by heating or one of the low hydrated form...

so next time before thinking that someone ignore your advices, try to understand what the people want

bye

[DrCMS]

the prep i have consist to react SOCl2 with the hydrated chloride salt...so why they use this quite harsh method if all the water goes off only at 110°? perhaps because they need extra dry cobalt chloride?

No idea but that was not what you asked about was it.

my initiial question was to know if it's the anhydrous compound that is made just by heating or one of the low hydrated form...

no your initial question was how to prepare anhydrous cobalt chloride, which I answered.

If you'd bothered to google what I told you to you would know that hydrated cobalt chloride CoCl₂.6H₂0 is rose pink while anhydrous cobalt chloride CoCl₂is blue.  I do not know of any low hydrated forms as I think you've just made that bit up.

so next time before thinking that someone ignore your advices, try to understand what the people want

If you'd asked for what you realy wanted right at the start it would have made it easier for all of us.  Next time you need to know something why not try looking it up yourself.  The information you needed is very easy to find if you'd tried.

[BluRay]

If you want a very low residual water in your compound you could dry it with compounds like P₄O₁₀, BaO, Mg(ClO₄)₂, CaO, silica gel,...