 Re: chloroform....
eh....i'm boed so i'll post it anyway,
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Cheapskate�s method for synthesizing Chloroform:
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Go get a five gallon bucket. The ones used for painting work well and are
available new, with a cover, in the paint department of most big homeowner
stores. The cover can be used to keep bird droppings and bugs out of the
reaction. Put the bucket outside in a reasonably ventilated area with good
drainage away from any shrubbery that can be killed by spills. Pour two gallons
of 10% sodium hypochlorite solution into the bucket. This material is available
in two one-gallon containers for around $4.00 from the local homeowner store in
the swimming pool section labeled, �Liquid Pool Chlorine.� Make sure you get the
Sodium Hypochlorite, not the Hydrochloric Acid that�s in the same section, HCl
is useful, but not for this reaction.
Add 5 pounds of ice to the Hypochlorite. Be careful pouring this stuff, it�s
bleach, but twice as strong as the stuff Mom uses to do your laundry. Each
splash on your clothing will eat a nice white hole. Stir with a plastic or
wooden spoon, avoid metal. Metal spoons won�t spoil the reaction, but it may
spoil the spoon.
While the solution cools, measure out 340 grams of acetone into a container. Add
about half of the measured acetone into the ice solution and stir it up. Wait
about 10 minutes and feel the side of the bucket. It should feel warmer near the
bottom and colder as you raise your hand to the ice. Stir the ice mix around and
equalize the temperature. Add the rest of the acetone and stir again. Let it set
for about 10 minutes.
If you didn�t listen and used less than five pounds of ice in the solution, it
will get hot enough to boil off the Chloroform and leave you with nothing but a
bad smell, splatters where it boiled over and probably holes in your shoes and
clothes. As a matter of fact it would be good to have an extra five pounds of
ice around in case you�re doing this in the middle of the day in Panama where
the temperature is hovering around 104F. At this temperature, or if you�re doing
this in the Peruvian Mountains at 6500 feet it may take more ice to keep it cool
enough not to boil off the Chloroform as it forms. This is a very exothermic
reaction, but it can be controlled easily by the addition of ice as needed.
You should have a cool mixture of ice and something that is starting to look
cloudy. It will be colder on the top than the bottom and most of the ice has
melted. Let this mixture set until the ice completely melts. Grab the bucket and
carefully pour off the water and fine white powder leaving behind the Chloroform
that has settled to the bottom of the bucket. When you�re pouring off the water,
it may be hard to see the Chloroform, but trust me, it�s in there. The
Chloroform is heavier than water and falls to the bottom in a bubble looking
blob. The blob will have a white powder clinging to it. Just pour off the water
until you can clearly see the blob and then pour blob, water and powder into a
smaller, easier to handle container. There may be some bubbles forming and
rising to the top of the solution. Don�t worry, this is normal and will not
cause a problem�unless you try to seal the reactants up.
Pour the Chloroform, powder and water through a coffee filter into a separatory
funnel and separate the crude Chloroform, which will sink to the bottom. You
will get around 200ml of crude Chloroform. Disappointed? This reaction uses very
cheap materials and is one of the simplest, cheapest methods known, so just quit
bitching and deal with it. Since the procedure is so simple up to this point,
make a few more batches before moving to the next step.
The Chloroform has water and the white powder still in it and this needs to be
removed. The Chloroform can be vacuum filtered through a six inch sand filter to
remove the powder and then passed through about 4 inches of anhydrous magnesium
sulfate to remove most of the water, but the mechanical loss would kill half of
the product. The best way to clean this up is to distill it. Use an
appropriately sized flask, a one liter two-necked flask will work well, even for
larger volumes. If you�re doing more than half a liter, pour it in as the
distillation progresses. Use a fractionating column, I use a 400mm, set up for
normal distillation with an oil bath and magnetic stirring. If this last
paragraph doesn�t mean a thing to you, go to the library and get an organic lab
survivor�s guide. These books have pictures and complete descriptions of all the
pieces I�ll talk about.
Remember, distilling Chloroform is not an incredibly safe procedure. Chloroform
fumes are toxic and narcotic, and may knock you out if aren't being careful. On
contact with flames and hot surfaces it can decompose into the dangerous war gas
phosgene. So ventilate the area with fans to remove the vapors and attach a vent
tube to the vacuum adapter that leads away from the area where you�re working.
It is interesting watching Chloroform distill through a fractionating column. As
the solution comes to a boil a gray cloud rises up the column until it reaches
the distilling head and spills into the condenser where it disappears into
fluid. Below the rising cloud the Chloroform condenses on the sides of the
column and drips back into the solution to be converted into the rising cloud
again. Keep the boil fairly slow, you don�t want to boil it dry while you�re off
visiting the bathroom or kitchen. The first Chloroform that comes over is
tainted with water, don�t worry about it, keep collecting. When the Chloroform
is almost gone from the source flask, add about 200 ml of water and bring to a
gentle boil to force the remaining Chloroform from the column (there�s a bunch
of stuff in there). You can tell when the Chloroform is done because the
temperature starts to rise pretty quickly from 60c to 80c. Stop the distillation
at this point.
As the Chloroform distilled it azeotropically carried over some water that can
now be seen as clear bubbles clinging to the sides of the receiving flask or
floating around on the top of the clear Chloroform. It can also cloud up the
Chloroform some. Pour the Chloroform into a separatory funnel. Put a flask
fitted with a filtering funnel loaded with a couple of inches of anhydrous
Magnesium Sulfate under the separatory funnel, and let the Chloroform slowly
drain through while separating the water. This will leave you with clear
anhydrous Chloroform in the flask.
To make anhydrous Magnesium Sulfate, get some Epsom Salts at the drug store and
pour about a pound into a casserole dish. Heat the casserole dish in the oven at
450F for about 4 hours. After cooling and chipping and crushing the fused
material you have anhydrous Magnesium Sulfate. Putting it in a thick plastic bag
and tapping gently with a hammer can crush this stuff. Use a butter knife to get
it out of the pan, not an ice pick! You can also line the pan with aluminum foil
to make removal easier, but sometimes it�s hard to get the aluminum loose from
the Magnesium Sulfate. Don�t grease the pan stupid!
Now look back at what�s left in the distilling flask. It�s got water and some
nasty green stuff clinging to the sides and a white powder setting on the
bottom. See why you distilled it? This crud would have been left in the
chloroform and screwed up everything you used it for.
Put your crystal clear, anhydrous Chloroform in a brown bottle, cap tightly and
store away from light. If you�re going to store it for a long time put a couple
of drops of 95% alcohol in to stabilize it. Warning, Chloroform will eat rubber,
so don�t use a rubber stopper. Glass or teflon seals are the best.
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2001-06-03, 10:13
i get that alot to jen 