Sciencemadness Discussion Board

"dry" acetone

Sandbag - 15-9-2005 at 16:43

What exactly is this "dry" acetone, and how might one go about converting normal liquid acetone to "dry" acetone?

ADP - 15-9-2005 at 17:16

Well generally, dry means without water, so I would assume well actually I know it means anhydrous acetone. A small amount of water is in OTC acetone thats why its referred to as dry.

Sandbag - 16-9-2005 at 01:10

So lab grade acetone would be as "dry" as it comes, correct? And anhydrous normally refers to a gaseous state, we're still talking about a liquid, right? Just liquid tone with little to no dilution in water.

Acetone

Kinetic - 16-9-2005 at 02:42

Quote:
And anhydrous normally refers to a gaseous state
I think you had better check up on that statement.

Lab grade acetone would not be 'anhydrous'. Howerver, it would not contain much water and is suitable for most uses as is. Futher drying must be done using a drying agent of some sort - for example, distilling your acetone from anhydrous calcium chloride. Acetone is a bit tricky since it can react with common drying agents such as CaH2, and probably also with Na and P2O5.

If you insist on the gaseous option, you can get really dry acetone by heating it in an open container to 100 degrees C or so.

Organikum - 16-9-2005 at 05:51

After my understanding "dry" may include traces of water as they come in by the usual humidity of the air, "anhydrous" is completely without any water.

Gaseous or liquid has nothing to do with it.

I wouldn´t use CaCl2 for drying acetone, the drying agent of choice is sodium carbonate.
Keep in mind that all drying of liquids takes time and stirring speeds the process up.

And yes: I would regard a fresh bottle bottle of labgrade acetone as "dry".

/ORG

kazaa81 - 16-9-2005 at 14:28

I'm having troubles getting acetone at hardware stores....they want to sell me what they call "acetone" even if it isn't wrote on the can containing it (some toluene and other dirt...)
Has anyone get success buying it in non-USA. Please consider i'm in holiday in Italy.

FrankRizzo - 16-9-2005 at 16:12

If you're drying the acetone for use in pyro, calcium chloride (Damp-Rid) works just fine. Funnel in ~1/2 cup per quart and wait a day or two before using it.

For syths or other uses, use 3A molecular sieves. Just pour a bunch into the can, and the sieves will soak up the water and a bit of acetone.

unionised - 17-9-2005 at 03:15

" the drying agent of choice is sodium carbonate"
Sounds like a synthesis of diacetone alcohol to me.
CaCl2 works well enough and, if you are fussy, distilling it will clean it up ver well.

mick - 17-9-2005 at 07:06

I have read that molecular sieve can cause self condensation of acetone which would produce water. I would not have thought it was very fast so drying overnight, decanting and distilling could give dry acetone but storing over molecular sieve might be a problem.
If you are doing water sensitive reactions carrying out a small scale reaction with dryish solvent first and distilling out the solvent before quenching etc might give you good quality solvent for the main reaction. A lot of variables though.

If you distil ethers and store them be careful, peroxides can form quite fast without the stabilizer even in a brown bottle.

mick

neutrino - 17-9-2005 at 13:07

Acetone is a ketone, not an ether.

new_chemist302 - 17-3-2006 at 21:01

Acetone can be dried by adding oven baked Epsom Salt to it, then filtering, or just leave the MgSO4 in the bottom of the acetone and decant off what you need.

turd - 18-3-2006 at 00:18

From "Purification of Laboratory Chemicals":

It can be dried with anhydrous CaSO4, K2CO3 or type 4A Linde molecular sieves, and then distd. Silica gel and alumina, or mildly acidic or basic dessicants cause acetone to undergo the aldol condensation, so that its water content is increased by passage through these reagents. This also occurs to some extent when P2O5 or sodium Amalgam is used. Anhydrous MgSO4 is an inefficient drying agent, and CaCl2 forms an addition compound. Drierite (anhydrous CaSO4) offers he minimum acid and base catalysis of aldol formation and is the recommended drying agent for this solvent.

(\em added)

FriendlyFinger - 18-3-2006 at 18:29

Then it says shake for a few hours with 25g/l CaSO4, decant and distill through a column with 10g/l CaSO4. Is Sodium Carbonate better?

FriendlyFinger - 27-6-2006 at 23:37

7) What's the story with molecular sieves and acetone?

"Purification of laboratory chemicals" 5th edition page 29 says;

"However, care must be exercised in using molecular sieves for drying organic liquids. Appreciable amounts of impurites were formed when samples of acetone, 1,1,1-trichloroethane and methyl-t-butyl were dried in the liquid phase by contact with molecular sieves 4A (Connett lab pract 21 545 1972)"

The book also sugests that MgSO4 is acidic enough to cause some adol condensation

In 3l of hardware acetone, I put a couple of spoon full of anhydrous MgSO4, that was boring so filtered that off after only 15 min, then put in 500g of freshly activated 3A molecular sieve beads and left over night.

Next day, poured into a flask and distilled. Started out at 56 deg and after about 2l had come over, temp was at 56.5 deg then with about 500 ml left, temp started shooting up to 60 deg, so I stopped.

Some of that acetone was used to gas some benign freebase and left the salt with an increadibly foul smell. 125ml of this acetone was vacuum distilled, bath at 25 deg wich left about 5ml of an oily substance with the same foul smell and it wasn't freebase because yield of salt was 94%.

After acetone was gone from the molecular sieves, they were put in the oven and the same foul smell started eminating. So I've probably got some diacetone alcohol and who knows what else.

turd - 28-6-2006 at 11:04

Quote:
"However, care must be exercised in using molecular sieves for drying organic liquids. Appreciable amounts of impurites were formed when samples of acetone, 1,1,1-trichloroethane and methyl-t-butyl were dried in the liquid phase by contact with molecular sieves 4A (Connett lab pract 21 545 1972)"

I stored dry acetone over mol sieves for 2 weeks and couldn't detect any condensation products neither by GC/MS nor by 1H-NMR. I wouldn't store it for longer than that though.
Quote:
Some of that acetone was used to gas some benign freebase and left the salt with an increadibly foul smell.

Why would you bubble a strong acid through acetone? Containing an amine of all things?

Organikum - 28-6-2006 at 12:00

After drying acetone with sodium carbonate I never detected any condensation products, but I admit that I simply not looked so much either. I buy my hardwarestore acetone which is some 98,8% min. trusting the datasheet, dry it with the carbonate, filter an distill. For serious synthesis I use only the middle run of the distilation, say some 80%. Was always perfect for me. The rest I use for cleaning purposes.

Anything wrong with this?

??
/ORG

cbfull - 28-6-2006 at 14:39

This is an interesting thread. I have read from some sources that acetone is tricky to dry, and another source stated that phosphorous pentoxide (P2O5, as stated earlier) should be used and then the acetone is distilled off. I don't think I would trust the P2O5, because the hydrolysis product is phosphoric acid.

It sounds like drierite is your safest bet, which has been freshly dried following the instructions for drying drierite exactly. Apparently, Drierite needs to be re-dried in a very specific way (temperature, time, etc.) for it to do a really good job.

Lab grade acetone is typically <0.5% water, which is not really too bad. I don't know exactly how dry it needs to be for whatever application, but there's my 2 cents.

battery - 29-6-2006 at 03:04

can any1 here give me any good recipies for good explosives and can you send me a list of chemicals used in home made explsovies eg.acetone and what they come under in shops and were to get them from talk on here or email me please

DrP - 29-6-2006 at 03:10

Excuse my ignorance, but what does KEWL mean? Does it mean fucking dick head who is likely to blow himself up?

enhzflep - 29-6-2006 at 03:29

Quote:
Originally Posted by DrP,
but what does KEWL mean? Does it mean fucking dick head who is likely to blow himself up?


Yeah, that's pretty much what I've always taken it to mean. Although, in a greater context it may taken to mean somebody who is exagerating and more likely to discuss items/topics designed to elicit the response "Cool!" This person most commonly knows very little on the topic of which they speak - though in the vast majority of cases they believe (and occasionally do) that they know vastly more than those subject to said speech.

This type of personality combined with what are usually gaping holes in knowledge is a deadly mix once added to this hobby.

Take for example the 15yr old boy from Sweden that blew himself up a number of years ago. He was all over RS.org talking about how he had all this AP and would mix it with some AN he had 'to make one big effen bomb'

A number of members told him to be carefull, and that that much AP was suicidal, but he disregarded them - too keen to take advantage of the fact he could impress his mates whilst mummy was away for the weekend.

Turns out that one night after posting, he did do himself a mischief - with 800gms AP no-less!!! A big mischief - DEAD.

He was waaaaay kewl.

Asking for freely available recipes, with no apparent effort to discern those that are bullshit from those that are genuine is quite definitely another manifestation. Is that what you were getting at DrP? ;)

[Edited on 29-6-2006 by enhzflep]

neutrino - 29-6-2006 at 14:13

The standardized definition of 'kewl' comes from the KGB files at RS. It's to long to post here, so follow the link and take a look if you're curious.

Now let's leave the old 'what is a kewl' discussion to the appropriate thread, and go back to our regularly scheduled thread about drying acetone...

cbfull - 29-6-2006 at 14:28

Can anyone tell me what kind of stuff would need acetone to be dry?

We have HPLC grade acetone at work which is <0.5% water, and if it has too much water in it then it won't dissolve the resins.

DrP - 30-6-2006 at 02:33

When I was doing my PhD, we distilled ALL solvents that were used in reactions - this eliminates ALL possibilites and arguments over wether or not trace amounts of water have effected your results. It's up to you, but my take on it would be - if in any doubt at all then distill it and be done with it - then you are sure and confident that you have dry product. Heck - stick one of the above mentioned drying aids in the bottom of the distillation flask as well to make sure. EZ (E-Z - get it? Kewl eh? )

Organikum - 2-7-2006 at 08:16

Thats what Vogel writes about drying acetone and MEK:
Quote:
The ketone is salted out from the distillate
with potassium carbonate, separated, dried with anhydrous potassium
carbonate (this will also remove traces of sulphur dioxide and carbon
dioxide present), and, after filtration, allowed to stand for several hours
over anhydrous calcium sulphate.


Vogel rulez!

/ORG

additional routes taken from vogels practical organic chemistry,5th edt

texas_holdem - 9-7-2006 at 15:47

-------------------------------------------------------------------------
KETONES

21.ACETONE
although major impurities in the commercial grades of actone are methanol,
acetic acid and water, the analytical reagent generally contains less than 0.1 per
cent of organic impurities although the water content may be as high as 1 per cent.
Commerciall acetone may be purified in several ways:
(a) The acetone is heated under reflux with successive quantities of potassium
permanganate until the violet colour persists. It is then dried with
anhydrous potassium carbonate or anhydrous calcium sulphate,*) filtered
from the desiccant and fractionated;precautions are taken to exclude
moisture.
(b) To 700mL of actone,b.p.56-57°C, contained in a litre bottle, a solution of
3g of silver nitrate in 20mL of water is added, followed by 20mL of 1M
sodium hydroxide solution, and the mixture is shaken for about 10 minutes.
The mixture is then filtered, dried with anhydrous calcium sulphate and
distilled.
(c) When only a relatively small quantity of oure, dry acetone is required, it
may be purified through the bisulphite complex: the latter is decomposed
with sodium carbonate solution (for details, see under 22.Ethyl methyl
ketone), dried over anhydrous calcium sulphate and distilled. A more
convenient procedure is to make use of the addition compound with sodium
iodide (NaI,3 C3H6O), which decomposes on gentle heating and is particularly
well adapted for the preparation of pure acetone. One hundred
grams of finely powdered sodium iodide are dissolved under reflux in 440g
of boiling commercial acetone, and the solution is cooledin a mixture of ice
and salt (-8°C). The crystals are filtered off and quickly transferred to a
dry distilling flask, connected to an efficient condenser and to a receiver
cooled in ive. Upon gentle warming, the acetone distills rapidly.

Acetone purified by these means, or the analytical reagent grade, may have
the water content reduced by storage over a Type 4A molecular sieve. Silica
or alumina should not be used as an aldol type reaction is initiated with the
formation of water as a by-product. Pure acetone has b.p. 56.2°C/760mmHg
and is highly flammable.

*) Anyhydrous calcium chloride should not be used as some chemical combination occurs

22.ETHYL METHYL KETONE (Butan-2-one)
This excellent solvent has properties similar to those of acetone but it has a
somewhat higher boiling point and is therefore less flammable. A preliminary
purification is effected by drying the commercial product with anhydrous
potassium cabonate or anhydrous calcium sulphate, filtering from the desiccant,
and fractionating through an efficient column; the fraction,b.p.79-80°C, is
collected seperately, and is quite satisfactory for recrystallisations, This may be
futher purified either through the bisulphite addition compound or through the
sodium iodide addition compound. The ethyl methyl ketone, b.p.79-80°C,is
shaken with excess of saturated sodium bisulphite solution until reaction ceases,
cooled to 0°C, the bisulphite complex filtered off, the filter cake well drained,
washed with a little ether, and then dried in the air. The dry bisulphite complex
is decomposed with a slight excess of sodium carbonate solution and distilled in
steam. The ketone is salted out from the distillate with potassium carbonate,
separated, dried with anhydrous potassium carbonate (this will also remove
traces of sulphur dioxide and carbon dioxide present and, after filtration,
allowed to stand for several hours over anhydrous calcium sulphate. It is then
distilled. In the sodium iodide method, the ketone is saturated with sodium
iodide by boiling under reflux, the solution is filtered through a hot-water funnel,
cooled in a freezing mixture and white crystals (which have a m.p. of 73-74°C)
filtered off. Gentle heating of the crystals in a fractional distillation assembly
gives pure ethyl methyl ketone of b.p. 79.5°C/760mmHg.
-------------------------------------------------------------------------
there u go.
this has just been typed off the 5th edt.
it is almost the same text as in the 3rd, only the introduction slightly differs.
im wondering whats the contaminant in hardwarestore-tone.
im asking as i remember someone posting he had some oily
yellow substance left in the flask when distilling his.
anyone distilling their 'tone?

angelhair - 8-9-2008 at 21:09

Can anybody confirm the efficency of Sodium carbonate and whether there are any condensation products?

Klute - 8-9-2008 at 21:38

I routinely use K2CO3 for drying and distilling acetone with good results. Anhydrous Na2CO3 should do th ejob well enough, although you might want to leave it a bit longer as it is less effective than K2CO3.

But i think the quality of the acetone required for most basic reactions is over estimated. A simple distn is more than enough in most cases. Keeping the acetone dry is more important than getting those last 0.5% water out IMHO.

panziandi - 9-9-2008 at 05:43

Indeed, for most purposes I just use aceone LR or BP grade fresh from the bottle and quickly replace the lid. If it specifies a very dry product shaking with some anhydrous K2CO3 is best, decant and distil into a flask closed to the atmosphere with a CaCl2 drying tube.

Panache - 10-9-2008 at 18:09

I might try some partially wetted acetone at -85 to see if the water freezes out. absolutely nothing is happening with ether

panziandi - 28-9-2008 at 12:40

That is a completely pointless post. Not everyone is a meth cook and this is not the home of meth cooks. This thread started as a question to clarify what was meant by "dry" in terms of solvents (specifically acetone). Dry acetone is very useful, e.g. for reacting with organo-metallics, wittigs the list is almost endless for moisture-sensitive reactions. Not to mention as a means to isolate hygroscopic amine HCls, not meth. Like this forum is about sciencemadness... not science that causes people to go mad and write gibberish nonsense on the threads.

Panache - 28-9-2008 at 17:10

i am surprised it was so well punctuated and spelled, i guess all the effort went into that, as opposed to the content.
I would like to tell Scienemadness members i believe acetone vapours are not directly harmful in small amounts and they should not worry about their health should they smell acetone. Its not HCN, to be avoided at all costs, and worrying about acetone vapours whilst making/taking drugs in a kitchen is similar to worrying about contracting SARS from the ambulance you have called to treat your life threatening burns from the kitchen fire after you stumbled carrying a casserole dish of boiling flammables whilst smoking.
And who are these 'real ppl' who apparently only dry ether not acetone. I am a real person, i think, and i dry acetone, Klute i think is a real person, he dries acetone apparently. I think i'll need greater proof of these real people before i stop drying my acetone.

That said in relation to my earlier post on drying solvents by subjecting them to -85C for sometime and decanting the solvent from the solid water. I also tried this with acetone (ether was unsuccessful as far as my experiemnts went). and had similar results. I have however emailed the collator of that water site i mentioned in Misc asking him about the concept of it, i feel there must a fundamental thermodynamic reason for it to fail rather than simply a kinetic one and the reason will vary from solvent to solvent depending on its relationship with water. Water is very very very complicated i have recently learned, did you know presently evidence indicates water gets around as (H2O)280 clusters and these clusters, highly organised, are constructed from units comprising of four, bicyclo octomers of the molecule we refer to as H2O, these octomers are the crystal form of ice7 of of the 17 crystal structures of crystalline ice, there are also 6 amorphous ices, of which ordinary ice is one, (all the crystalline varieties have below parity density) and common amorphous ice, compared with liquid water, has a 100fold poorer capacity to resonant with the microwave radiation typical of the kitchen microwave, explaining why defrosting in the microwave sucks so bad!!
Anyway will update if the dude gets back to me.

[Edited on 28-9-2008 by Panache]

vulture - 3-10-2008 at 15:13

Will you people get back to the topic at hand or kindly STFU. Panache, your nonsense is getting irritating. Cut it out or be cut out from the board, your call.

angelhair - 15-10-2008 at 00:39

How hygroscopic is dry acetone?

If you used K2CO3 to dry it and then left the acetone in an open beaker for a few hours would it soak up enough water to call it reasonably wet?

[Edited on 15-10-2008 by angelhair]

jarynth - 15-10-2008 at 03:33

After a few hours in an open beaker I would call it reasonably gaseous.

Besides, I wouldn't use bases to dry ketones. But if you only have K2CO3, you can make a better drying agent (for alcohols etc) by roasting it. You will also get some decomposition to KOH.

[Edited on 15-10-2008 by jarynth]

Klute - 15-10-2008 at 10:21

K2CO3 is perfectly suiatble for drying ketones. Just read "Purification of Laboratory Chemicals". It is even prefred to Na2SO4 or MgSO4 as it causes less aldol condensation.

I don't understand what you mean by a "bbetr drying agent". Anhydrous K2CO3 in anhydrous K2CO3. heating it in an oven isn't going to change much, unless it is already partially hydrated. But it is assumed the anhydrous salt is used. KOH, even in traces, is going to be very bad for acetone and ketones.

Drying acetone and leaving it in the open air for a few hours is a bit pointless. Better just dry it and keep it in a closed bottle, or at least in a covered beaker. It will absorb some water, depending on your ambient humidity, but not as much as say absolute ethanol. Depending on the quality of the acetone you get in the first place and your needs, you might betetr be off using it directly in that case. Better just dry it correctly, and keep it as such.

Keeping acetone over K2CO3 isn't a good idea because it is easily suspended and somewhat slow to decant, so you will poor fine K2CO3 with your acetone when you use it.

jarynth - 15-10-2008 at 11:37

Quote:
Originally posted by Klute
K2CO3 is perfectly suiatble for drying ketones. Just read "Purification of Laboratory Chemicals". It is even prefred to Na2SO4 or MgSO4 as it causes less aldol condensation.

Please disregard my post, I didn't read the whole thread. I guess what I was thinking was that K2CO3 is very hygroscopic, so you'd have to dehydrate it before use.. but this may cause the formation of the oxide (or hydroxide), with all the consequent problems.

Klute - 15-10-2008 at 12:24

Well, in order to be sure the salt is an anhydrous as possible, it always best to dry it at 100°C for a while depending on how you store it, but for routine drying like this it's genrally not needed.

By the way, I have always found it to be better to add a little Na2SO4 or MgSO4 before adding K2CO3 to a very wet organic, as K2CO3 can form a thick liquid when in presence of too much water. Adding a little sulfate avoids this, as the K2CO3 clumps arounf the sulfates at first, then get free as it absorbs the water correctly. I have always found K2CO3 much more quick and effective than the sulfates. Hope it cna help.

Panache - 15-10-2008 at 18:41

Quote:
Originally posted by jarynth
After a few hours in an open beaker I would call it reasonably gaseous.

Besides, I wouldn't use bases to dry ketones. But if you only have K2CO3, you can make a better drying agent (for alcohols etc) by roasting it. You will also get some decomposition to KOH.

[Edited on 15-10-2008 by jarynth]


So k2CO3 will go to KOH with heat, will it completely convert. KOH is always annoying in melbourne i have found, its either the high prices of the chem suppliers or the inconvenience of a solution. i will check vogel firstly, sry thinking out aloud.

jarynth - 16-10-2008 at 00:22

Well, after roasting the carbonate (small prills, about 300 microns) for a while I got a light powder that reacted noisily upon solution in water with the generation of heat, much like NaOH does, but not as vigorously.

I did weigh reagent and product but, not knowing the exact degree of hydration of the carbonate, I wasn't able to compute with certainty the molecular mass of the product. I suspect I got a mixture containing K2CO3, K2O, KOH, KO2, etc.

Can't you make the hydroxide by the reaction of the carbonate with Ca(OH)2? Or by heating the sulfite, bisulfite... followed by quenching in water?

blogfast25 - 17-6-2010 at 07:05

Here's a bit of a conundrum for all you 'pro acetone driers': my acetone after use (drying ZrOCl2.8 H2O crystals) contains water, FeCl3 and some... HCl! I could just dump it but not having much to begin with I'd like to recycle as much as possible.

Having overlooked the HCl, you can imagine what happened on addition of anh. Na2CO3! To stop the foaming (the smell of acetone became very strong) I had no choice but to add some NaOH, ending up with a bottom of mainly NaCl, NaOH, Fe2O3. I cautiously distilled (after filtering, of course) it and it came over at 57.4 C.

There must be a better way though to get shot of the HCl...

not_important - 17-6-2010 at 08:09

Pretreat with CaCO3, even gardening limestone. Add just a little and stir for awhile, then add a little more and repeat until bubbling stops. Let it settle, if there was a lot of HCl then there may be some concentrated CaCl2 solution making the excess CaCO3 pasty, no harm; the iron will colour the excess carbonate s\as it falls out of solution. Decant through a filter and then dry the filtrate with soda ash or K2CO3.




blogfast25 - 17-6-2010 at 12:58

Good idea! :) But what would be wrong in adding quite a lot of CaCO3 (say 10 g/100 mL of acetone?) in one go, perhaps in a wide bottomed flask (thus improving contact), decanting/filtering off and then adding the drying agent? I've got just the kind of limestone for it, quite a 'pure' variety...

not_important - 17-6-2010 at 17:04

Plop plop fizz fizz ...


keep the fizzing and foaming down by starting off with a small amount. Note that crushed limestone is courser and should react slower, and may be OK to just dump in. Marble or limestone bits are used to neutralise the HBr/HCl from brominating/chlorinating acetone or other simple ketones, it's not reactive enough as a base to give bothersome condensations (but the hydrogen halide is acid enough to cause problems)



blogfast25 - 18-6-2010 at 07:33

Marble is exactly what I've got, nice little pebbles of just the right reactivity... :)

bbartlog - 18-6-2010 at 16:04

Quote: Originally posted by not_important  
Pretreat with CaCO3, even gardening limestone. Add just a little and stir for awhile, then add a little more and repeat until bubbling stops. Let it settle, if there was a lot of HCl then there may be some concentrated CaCl2 solution making the excess CaCO3 pasty, no harm; the iron will colour the excess carbonate s\as it falls out of solution. Decant through a filter and then dry the filtrate with soda ash or K2CO3.


I think I would distill just because acetone forms condensation products when exposed to HCl, even at room temperature. Maybe if there wasn't a lot of HCl and it hadn't been sitting long?

blogfast25 - 19-6-2010 at 06:02

Oh but yes: the recycles acetone will be redistilled, if only to get rid of some residual salts/solids.

blogfast25 - 3-7-2010 at 06:44

Well, well, well, the first attempt at drying acetone previously used to dry and extract small amounts of FeCl3 from ZrOCl2.8 H2O is yielding an interesting result.

I added a few marble size pieces of actual marble to about 400 - 500 mL of used acetone, to eliminate HCl. Bubbling started right away: not vigorously but noticably and steady nonetheless. That was last night.

Today about 18 h later and the system has developed in a two phase liquid/liquid system, with lighter coloured opaque and heavier liquid sitting underneath a pale yellow opaque phase. It's a true two phaser: shaking up the bottle briefly disperses the phases but they separate back very quickly. Water and acetone are supposed to be miscible in all ratios.

Marble and HCl of course form CaCl2, water and CO2. Is it possible the formed CaCl2 is a solubility suppressant for acetone in water? I'll test this idea independently...

Assuming the heavier phase is watery then it's probably quite rich in CaCl2 by now...


[Edited on 3-7-2010 by blogfast25]

blogfast25 - 5-7-2010 at 08:34

I separated the small heavier fraction (w/o attempt at analysis - lack of time). The supernatant liquid was perfectly clear and pale yellow (due to the Fe3+). I added a small amount of 'bottom' fraction (BP = 88 C) from a previous nail polish distillation and some more bubbles appeared: Ca(HCO3)2 reacting with some acidity in the 'bottom'? I added the marble again and got some more CO2 for about 10 mins, at the end of which the liquid had turned an amber - reddish colour, presumably due to hydrolysis of Fe.nH2O(3+)..

The marble removed, 20 g of anh. Na2CO3 was then added and shaken regularly, no CO2 eluted. After a couple of hours the liquid had cleared up completely with hydrated ferric oxide at the bottom and the Na2CO3 solidified completely. It was left standing overnight. After filtering the BP was established at about 62 C and the 400 (or so) ml distilled off at about 57.5 C.