Actinium
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questions about my chloroform
I had made some chloroform via Haloform reaction of Aceton (dry) with 1L of 8.25% Sodium Hypochlorite. I have left the Chloroform in the container
with some of the left over water from the post reaction, (don't ask).
I finally have some time to set my rig up and distille. I'm sure that HCL has evolved and needs neutralizing. Should I be worried about Phosgene?
would washing it with Dh20 a couple of time then washing with saturated Sodium Carbonate or Bicarbonate solution to neutralize the HCL? dry and
distille and store Properly?
Or should it be properly destroyed and started over?
It was stored in the bleach bottle, in my basement where it is very cool especially this time of year and no light other than from a 60w bulb.
-Ac-
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Jylliana
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I don't think you have to worry much about Phosgene, since it's formed due to UV radiation. As long you keep the liquid away from too much sunlight,
you should be fine.
I'm not sure about the HCl... maybe someone else can help you with that.
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macckone
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Sodium bicarbonate solution is used to neutralize phosgene. Ethanol will also neutralize phosgene.
Phosgene requires oxygen and light to form from chloroform.
UV light is more efficient but lower frequency light can cause the reaction as well. Without UV it is unlikely to have formed in a few days.
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Amos
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How long ago was this haloform reaction done? If it's only been a few days, you probably don't have a lot to worry about. When you said you left it
with some leftover water from the reaction, do you mean some of the aqueous layer that was on top of the chloroform after the reaction? That's got
NaOH in it as a product of the reaction, which will not only neutralize acid such as HCl(which really shouldn't be there at all), but probably is
slowly destroying your chloroform.
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CuReUS
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yes by forming diethyl carbonate ,but it will give HCl as a by product
http://en.wikipedia.org/wiki/Diethyl_carbonate
[Edited on 30-10-2014 by CuReUS]
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Actinium
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wouldn't it be better to neutralize with saturated sodium Carbonat or Bicarbonat and use ethanol to stabilize it?
Is 95%-96% ok or does it need to be anhydrous EtOH?
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aga
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Introducing Water isn't great, due to :-
1. the other side reactions that may occur (actual knowledgeable person fill in here please)
2. a Pure reagent is better to have, as you Know what is in it.
In any case you'll need to add some ethanol or an alternative (akpfihp) to neutralise any phosgene that forms.
If you do not Need the chloroform, dump it back into the reaction liquid and leave it for a week or so before flushing.
Chloroform should be prepared for Use rather than Long-Term Storage, as it decomposes over time.
A bit like making a sandwich today so you can have a packed lunch next month.
I have a bottle of 1-month old packed lunch in a drawer, and feel sure i'll have to make some fresh before use.
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Amos
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Quote: Originally posted by aga  | Introducing Water isn't great, due to :-
1. the other side reactions that may occur (actual knowledgeable person fill in here please)
2. a Pure reagent is better to have, as you Know what is in it.
In any case you'll need to add some ethanol or an alternative (akpfihp) to neutralise any phosgene that forms.
If you do not Need the chloroform, dump it back into the reaction liquid and leave it for a week or so before flushing.
Chloroform should be prepared for Use rather than Long-Term Storage, as it decomposes over time.
A bit like making a sandwich today so you can have a packed lunch next month.
I have a bottle of 1-month old packed lunch in a drawer, and feel sure i'll have to make some fresh before use. |
Aga, you can keep it indefinitely, actually. You just might need to wash it with sodium bicarbonate and redistill/dry it, but that's way less work
than starting from scratch again.
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vmelkon
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This is the equation for the reaction
CH3COCH3 + 3 NaOCl => CHCl3 + CH3COONa (sodium acetate) + 2 NaOH
so, there is no need to worry about HCl.
You can even dry the CH3COONa and NaOH and perhaps figure out how to separate them.
This is my video for chloroform
https://www.youtube.com/watch?v=HtW1IfdTiB0
[Edited on 31-10-2014 by vmelkon]
Signature ==== Is this my youtube page? https://www.youtube.com/watch?v=tA5PYtul5aU
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bbartlog
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I've gotten some quite unpleasant whiffs of what I guess was minute quantities of phosgene (plus HOCl/HCl or whatever else gets generated alongside)
from a clear glass bottle of chloroform (~250ml) that was sitting in a garage for a week, exposed to diffuse daylight. It didn't smell like that when
I put it away. I wouldn't regard the danger as negligible if you store it without some kind of additive to neutralize the phosgene. I've since
switched it to a brown glass bottle and added a bit of methanol.
The less you bet, the more you lose when you win.
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Actinium
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| Quote: Originally posted by No Tears Only Dreams Now | | Quote: Originally posted by aga | Introducing Water isn't great, due to :-
1. the other side reactions that may occur (actual knowledgeable person fill in here please)
2. a Pure reagent is better to have, as you Know what is in it.
In any case you'll need to add some ethanol or an alternative (akpfihp) to neutralise any phosgene that forms.
If you do not Need the chloroform, dump it back into the reaction liquid and leave it for a week or so before flushing.
Chloroform should be prepared for Use rather than Long-Term Storage, as it decomposes over time.
A bit like making a sandwich today so you can have a packed lunch next month.
I have a bottle of 1-month old packed lunch in a drawer, and feel sure i'll have to make some fresh before use. |
Aga, you can keep it indefinitely, actually. You just might need to wash it with sodium bicarbonate and redistill/dry it, but that's way less work
than starting from scratch again. |
How much Sodium Bicarbonate did you use in your solution and how much of this solution did you use to wash? I can't find anythinf on this and guess
its my lake of creative wording that prohibits me from succeeding.
As always, thanks guys for all the replies and imput.
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vmelkon
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| Quote: Originally posted by bbartlog | I've gotten some quite unpleasant whiffs of what I guess was minute quantities of phosgene (plus HOCl/HCl or whatever else gets generated alongside)
from a clear glass bottle of chloroform (~250ml) that was sitting in a garage for a week, exposed to diffuse daylight. It didn't smell like that when
I put it away. I wouldn't regard the danger as negligible if you store it without some kind of additive to neutralize the phosgene. I've since
switched it to a brown glass bottle and added a bit of methanol.
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What's preventing you from putting the bottle in a cardboard box, shielded from light? You can even store it in a freezer to reduce the rate of any
chemical reaction.
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We must attach the electrodes of knowledge to the nipples of ignorance and give a few good jolts.
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greenlight
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I have also heard to store the chloroform in a bottle where it can be as full as possible with almost no air gap to reduce the chance of conversion
with oxygen if it is to be stored for longer periods.
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Amos
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Limiting the amount of headspace at the top is also supposed to be a good idea. As for how much sodium bicarbonate, as you asked earlier, Actinium,
it's not very big of a deal how much you use. Impurities, dangerous or not, are not likely to be present as a significant percentage of the liquid
unless your chloroform is positively ancient, so any considerable amount (let's say you wash a liter of chloroform with 100mL of water containing 10
grams of sodium bicarbonate; that would be even more than is necessary, but would still get the job done and wouldn't involve wasting much money or
sacrificing purity). Phosgene doesn't want that badly to form; chloroform vapour requires oxygen and an initiator(I think that's the right word) like
sunlight to form phosgene. If you limit the light exposure and the amount of headroom for vapor formation, you're not going to cause a chemical
disaster.
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