Hexavalent
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Odd Result for Haloform Reaction
I added 2L of generic household bleach (about 5%, recently used for the prep of crude triiodomethane with good results) to a 3L Erlenmeyer and set
outside. A ring stand was set up above it and 40ml acetone, recently distilled, was added to the top. It was added into the flask, with occasional
swirling, at a rate of a few drops per minute. Towards the end, it was increased to short bursts every five minutes. The liquid went cloudy as
expected. The reaction vessel felt slightly warm, and was placed in a bucket surrounded with ice packs and water to stand. A watchglass was placed
over the top.
The mixture was allowed to sit for 15 minutes, stirring occasionally with a long glass tube. I pulled out the flask after this time to inspect it and
found that a white solid was on the bottom of my flask. What is this? Any ideas?
"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
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Fossil
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Maybe NaOH or Na(CH3COO) since they are the only salts produced [CH3COCH3 + 3NaOCl --> CHCl3 + 2NaOH + Na(CH3COO)], however that is extremely
unlikely unless you lost liters worth of water during the reaction. The more likely reason is that you have a contaminant in your bleach.
[Edited on 2012-7-2 by Fossil]
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Hexavalent
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That's what I thought....is there a way to determine the assay of my bleach using medium-advanced chemicals and equipment, to find out what's going
on?
"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
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barley81
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Are you absolutely sure that it is a solid? The suspension of chloroform produced by the reaction can sometimes look like a solid is settling out.
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Hexavalent
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It could well be - I'll have a look tomorrow and investigate further. It looked like a fine powder earlier, but you could be right.
"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
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woelen
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Is the household bleach a thin non-viscous liquid? Where I live, there are two kinds of bleach. We have the cheap stuff, which is liquid like water
and we have somewhat more expensive stuff, which is quite viscous and which sticks to surfaces such that the bleach acts on the surface for a longer
time. Both contain the same amount of NaOCl. For chemical experiments, the cheap stuff is useful, the other stuff contains too much crap and is not
suitable for chemical experiments at all. Maybe your bleach also contains contaminants like what I described?
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vmelkon
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I had performed this experiment a few months ago, but I used NaOH + ethanol + iodine.
The stuff that forms looks almost white at first. It settled at the bottom. As the months go by, I it gets yellower and so does the solution on top of
it.
The picture on wikipedia looks extremely green but I saw another picture that prepared iodoform the same way I did. It looks almost white, just like
mine.
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Hexavalent
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Are you referring to chloroform or iodoform, vmelkon?
"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
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