vano
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Grow insoluble selenite crystals
Hello! a few days ago I grow some crystals of copper selenite dihydrate. as I remember solubility of this compound is 0.003g/100ml. I made copper
selenite a few times and of course, it forms just powder when solutions are mixed.
crystals aren't big but not bad I think. the method is easy. I dissolve water-insoluble selenite in sulfamic acid, I use a small amount of sulfamic
acid. then I dilute the solution and add some carbonate. the solution was clear blue. after hours small crystals formed. when the solution is
concentrated crystals don't form.
[Edited on 5-10-2022 by vano]
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DraconicAcid
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It looks like you've got a mix of green and blue crystals- are you sure you've only got one product?
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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vano
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this was the first experiment, it contained some carbonate, I added much more than it needed I think.
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unionised
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I realise it's not the same thing but the use of sulphamic acid reminds me that I made some nice crystals of calcium sulphate by mixing HCl CaCl2 and
sulphamic acid.
The sulphamate hydrolyses slowly to form sulphate which precipitates out gypsum.
But, because it's slow you get half decent crystals of it.
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