Fidelmios
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Potassium Ferricyanide Decomposition Question
(Spelling mistakes ahead, my autoreplace has turned against me)
Hi all,
I recently bought some potassium ferricyanide from a pottery supply store, in hopes of recrystallizing into a large mass. All the resources ive found
tell me to only use warm water, and avoid heating too much, or it will produce HCN. Im not sure if this is just a regurgitated source, or is there any
danger to heating a saturated solution on a stove/lab microwave. I made a saturated solution using boiling water already, and im not dead yet! My
question is about reheating the solution, I let it set too long and yhe bottom of my container is now covered in an inch of crystalline mass. I just
need to reheat the solution and start fresh, but am i in danger of HCN, or anything else outside of thermal shock to my glassware?
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gdflp
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There is no danger of HCN unless you heat the compound with a strong acid. The coordination between the cyanide ions and the central iron atom is
quite strong; as a result the molecule can only be hydrolyzed fully with strong acids and prolonged heating(See the Preparations of cyanide thread for
an example of this reaction). I would be amazed if a measurable amount of HCN was formed by boiling a saturated ferrocyanide solution for extended
periods of time, certainly not a worrisome amount.
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Fidelmios
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Quote: Originally posted by gdflp  | | There is no danger of HCN unless you heat the compound with a strong acid. The coordination between the cyanide ions and the central iron atom is
quite strong; as a result the molecule can only be hydrolyzed fully with strong acids and prolonged heating(See the Preparations of cyanide thread for
an example of this reaction). I would be amazed if a measurable amount of HCN was formed by boiling a saturated ferrocyanide solution for extended
periods of time, certainly not a worrisome amount. |
Yeah I thought that there was little worry, especially since I had to dissolve the salt in boiling water. I couldn't find one source that state a
decomposition temperature near obtainable by an oven/microwave. Like I said, most websites just said that the danger exists, and to only use warm
water. Thank you for the reply!
EDIT: Also 2 star level Obligatory 2 Star Gif
[Edited on 18-10-2016 by Fidelmios]
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