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Aluminium Trichloride

Hexavalent - 31-12-2011 at 09:16

Yes, I know that there have been many threads on this sort of thing but can never seem to work out one thing; is aluminium trichloride a solid or liquid at RTP? Wikipedia says its a solid, but what's all this about preparing anhydrous AlCl3 with a condenser?

kavu - 31-12-2011 at 09:25

Aluminium trichloride is a pale yellow solid at room temperature. Synthesis temperatures are usually so high that AlCl3 melts, hence the condenser.

Aluminium Trichloride

Hexavalent - 31-12-2011 at 09:36

Ah, I see. I assume this is why people want to prepare the anhydrous form;

Melting Point Data for Aluminium Trichloride

192.4 °C *(anhydrous)
0 °C (hexahydrate)

But what's wrong with reacting HCl with Al foil, evaporating a little and then transferring into a dessicator for drying and possibly storage?

woelen - 31-12-2011 at 09:43

Pure aluminium trichloride is a white solid. The yellow color is due to impurities. The hexahydrate is a colorless solid.

Hexavalent - 31-12-2011 at 09:46

That's what I thought. I read somewhere that the yellow colour comes from iron trichloride contamination.

Also, Woelen, how do I have my statement/bio come up on all my posts?

kavu - 31-12-2011 at 10:29

Quote: Originally posted by Hexavalent

But what's wrong with reacting HCl with Al foil, evaporating a little and then transferring into a dessicator for drying and possibly storage?

Problem is that aluminium trichloride is a strong Lewis acid. Aqueous solution of aluminium chloride contains coordinated species, such as [Al(H2O)6]3+. Heating will lead to decomposition and formation of HCl, Al(OH)3 and H2O. Anhydrous aluminium chloride can not be obtained from aqueous solutions.

peach - 31-12-2011 at 12:52

Quote: Originally posted by Hexavalent

Yes, I know that there have been many threads on this sort of thing

There are indeed many threads.

And you have clearly not read them, at all. Made only more annoying by the fact you've referenced your knowledge of them and then opened another thread.

For instance;

Quote:

But what's wrong with reacting HCl with Al foil, evaporating a little and then transferring into a dessicator for drying and possibly storage?

I answered that precise question, in detail, in one of those threads.

Which was it's self, a repeat of the same question.

That wiki article needs editing to include; "You cannot make anhydrous AlCl3 by boiling it down".

{edit} Hang on, it does!

Quote:

Hydrated aluminium trichloride is prepared by dissolving aluminium oxides in hydrochloric acid. Heating this solid does not produce anhydrous aluminium trichloride, the hexahydrate decomposes to aluminium oxide when heated to 300 °C

And that;

Quote:

Aluminium chloride is manufactured on a large scale by the exothermic reaction of aluminium metal with chlorine or hydrogen chloride at temperatures between 650 to 750 °C

If you'd paid a moments interest to the other many threads mentioning the fact that it is a gas when produced this way, you'd know why it needs some form of condensing surface.

Merge or delete.

[Edited on 31-12-2011 by peach]

Hexavalent - 31-12-2011 at 13:23

The thing is, so many people say so many different things that its difficult to keep track of what's going on with different procedures. I am relatively new to these forums (but not to chemistry) and am unsure of how to merge threads. Help?

(Additionally, I find it totally unnecessary to word your response in an almost offensive fashion.)

peach - 31-12-2011 at 13:41

Quote:

I am relatively new to these forums (but not to chemistry)

Undergraduates at university (18-21 year olds) will have used AlCl3 and noted the fact that it's a solid at room temperature. I've not done chemistry at university, and I realize it's a solid at room temperature, and know the answers to those questions you've repeated. So you can't be all that experienced to be lagging so far behind a theory noobster like myself, who's education in chemistry beyond A-Level comes purely from this forum, google and my own practical work at home.

Go to SIGMAALDRICH.COM

Type "AlCl3" into the search box.

What units are the packs sold in? And what's the description?

That's how hard it was.

Quote:

I find it totally unnecessary to word your response in an almost offensive fashion

It is an offensive, against sheer laziness.

[Edited on 31-12-2011 by peach]

Hexavalent - 31-12-2011 at 13:46

My sheer laziness? You have not actually answered my question in hand . . how to merge or delete posts. I am new to this forum and as home science enthusiasts we should be helping and encouraging each other, as opposed to being rude and discouraging others.

peach - 31-12-2011 at 13:47

You can't merge threads, the moderators do it when people keep opening threads that are identical to one another.

Hexavalent - 31-12-2011 at 13:52

Thankyou, that was the only answer I wanted and was needed.

Panache - 2-1-2012 at 19:11

Quote: Originally posted by Hexavalent

The thing is, so many people say so many different things that its difficult to keep track of what's going on with different procedures. I am relatively new to these forums (but not to chemistry) and am unsure of how to merge threads. Help?

(Additionally, I find it totally unnecessary to word your response in an almost offensive fashion.)

And what makes you think by opening up another thread you will not simply receive the same 'many' people saying the same 'many' different things.

The reality is most likely that you were simply too lazy to sift through the readily available information to glean what you needed and hoped that by asking, someone would do this for you.
Except you were not honest, you would have received better reception had you said, 'hey i'm lazy can you spend time answering my question so i can spend more time punking around with my cooljam'.

Instead when confronted about your drivel you retreat to the time honoured tradition of takers, that being, attempting to invoke sympathy via the 'poor me' approach.
Ffs get a job at reception somewhere and put all this out of your head or get some intiative.

No offense intended to anyone working in reception.

Neil - 3-1-2012 at 05:52

Well said Panache.

In any good thread the writers have likely taken hours out of their days on several occasions to fact check and add comprehensible usefull data. Peach and his posts. Hours? I have a feeling it takes him tens of hours to condense his picture sessions and likely hours more to do the write ups. This is ignoring the dozens of hours of reaserch that he would have done to have his little photo session and the dozens of hours to set up everything and verify it won't kill him. Really SM is just lucky that he has not realized that he could make more money and have more fun taking pictures of appreciative naked ladies.

Ever climbed a mountain? Home chemistry is a mountain. We all struggle to find what we can, asking to be spoon fed is like jumping on a sherpa(yes Peach, you are now a sherpa) and prodding him with your heels while pointing up the mountain and saying "giddy up"

Besides the disrespect of having onces previouse work being dis-regarded there is a safety aspect. No one here wants to inadvertantly contribute to someones injury or injury of others via that individuals ignorance. Anyone who can not read up on a couple of freelygiven pages of know-how/what can not be trusted to go out and gather all relivant safety data before mixing thing. Any such mishaps reflect very harshly on the whole of home science and can bring about further restriction. I wouldn't get pissed at Peach, I would just do more leg work next time and as Panache said, own your mistakes and intentions.

Almost every forum member here did the same thing as you when they started on the forum - they ether learned and are still here or they got upset and left. Those that stayed are often brilliant in there own way and are accepted.

[Edited on 3-1-2012 by Neil] Edit: miss hit end while still writing

[Edited on 3-1-2012 by Neil]

how to make aluminum trichloride

AndersHoveland - 3-1-2012 at 14:16

I had an idea for making anhydrous aluminum chloride. Place a piece of aluminum foil into ethyl ether. Then bubble in chlorine gas that has been passed through loose calcium chloride to remove any traces of moisture. The chlorine gas should react with the aluminum (without needing to be heated), and the resulting aluminum trichloride will dissolve into the ethyl ether. "Solutions of Aluminum Chloride in Ethers", Gordon G. Evans, Thomas R. P. Gibb Jr., J. Kevin Kennedy, Frank P. Del Greco

A similar procedure is already used for making anhydrous zinc chloride.

peach - 3-1-2012 at 14:34

I tried that with dichloromethane and hydrogen chloride.

I was not able to check the results well enough and it could have benefited from better drying (e.g. drying the DCM over calcium hydride). However, the solid material I did recover was fuming to some extent.

I recall suggestions of activating the aluminum with iodine or mercury chloride. I may give it another try, this time with one of those present.

Within the masses of information already posted there have also been mentions of drying it by co-distillation.

The solvent method would be particularly nice if it can be made to function as it would be easy to generate it in place - within the flask where it needs to be - avoiding the need for special distillations, extremely hot tube reactions, recollecting the solid and then transferring it through the air, where it'll start reacting again en route.

However, as with many theorized methods, I do agree with Len and the others that less talk and more action is required. So won't speculate any further on it until it's actually been run again in front of me.

neptunium - 3-1-2012 at 15:33

i was going to bubble dry chlorine gas in carbon tetrachloride with aluminum powder (500mesh) suspended and stirred constantly....i have yet to make CCl4 from chloroform and chlorine....

entropy51 - 3-1-2012 at 16:43

Quote: Originally posted by AndersHoveland

I had an idea for making anhydrous aluminum chloride. Place a piece of aluminum foil into ethyl ether. Then bubble in chlorine gas that has been passed through loose calcium chloride to remove any traces of moisture.

My recollection is that ethyl ether is not inert to chlorine. I vaguely recall something about explosive products being produced.

neptunium - 3-1-2012 at 17:08

sounds like a set up! run!!!!!

AndersHoveland - 3-1-2012 at 18:26

Quote: Originally posted by neptunium

i was going to bubble dry chlorine gas in carbon tetrachloride with aluminum powder (500mesh) suspended and stirred constantly....i have yet to make CCl4 from chloroform and chlorine....

The aluminum chloride would have to be soluble in CCl4, which I am not sure that it is, otherwise the reaction would not be able to proceed.

Chlorine gas does not react with ethyl ether, at least not in the dark. But it is probably not a good idea to leave ethyl ether in contact with chlorine for more than an hour, as chlorinated products will tend to form.

Ethyl hypochlorite, however, can be formed by passing chlorine into a solution of water, ethyl alcohol, a limited quantity of sodium hydroxide. Methyl hypochlorite is a dangerously sensitive explosive.
Journal of the Chemical Society, Volume 50, p607

Ethyl hypochlorite reacts with sulfur dioxide to form ethyl chlorosulfonate, CH3-CH2-O-SO2Cl, which is similar to ethyl sulfate in reactivity, although I am not sure if it is as hazardously toxic.

[Edited on 4-1-2012 by AndersHoveland]

unionised - 4-1-2012 at 04:40

Mixtures of Al with CCl4 can be detonated.

neptunium - 4-1-2012 at 20:06

glad i didnt try it then...i`ll pass Cl2 onto Al in a glass chamber then!

Neil - 4-1-2012 at 21:44

You might want to read the mentioned threads first.

neptunium - 4-1-2012 at 21:52

yup

[Edited on 5-1-2012 by neptunium]

peach - 5-1-2012 at 00:30

You forgot to warm it up?

AndersHoveland - 5-1-2012 at 01:03

If you simply try "reacting" aluminum with chlorine, there is not going to be any observable reaction. The layer of aluminum chloride that forms on the surface will prevent further reaction. Only two ways to avoid this. Either use a solvent that can dissolve the AlCl3 as it forms, or ignite the aluminum so that it burns in the chlorine gas. The first of these would be much more practical, as I suspect it may be rather difficult to get aluminum to ignite in the chlorine (unless a burning piece of magnesium ribbon is used).

[Edited on 5-1-2012 by AndersHoveland]

Lambda-Eyde - 5-1-2012 at 01:39

With a proper tube furnace the preparation would be facile. Substituting HCl for the chlorine would allow the reaction to proceed at a lower temperature, but hydrogen would obviously be the byproduct.

I have yet to see anyone perform a low-temperature reaction in a solvent to produce AlCl<sub>3</sub>. You'd have to find a solvent that's inert to Al powder, chlorine gas and the trichloride. Halogenated solvents don't like metals (although I don't know how bad Al is compared to, say Na), aromatics react with chlorine in the presence of lewis acids and so on... Peach's experiment with HCl in DCM didn't turn out to be a success, either.

franklyn - 5-1-2012 at 01:46

Quote: Originally posted by unionised

Mixtures of Al with CCl4 can be detonated.

With any luck, just ask member Zinc
http://www.sciencemadness.org/talk/viewthread.php?tid=5777#p...
http://www.sciencemadness.org/talk/viewthread.php?tid=5777#p...

Industrially this has only been known to occur in large vat quantities
It might be possible to sensitize the mixture by adding a pinch of Iodine
but try this only on miniscule quantities without containment.

.

AndersHoveland - 5-1-2012 at 12:55

Quote: Originally posted by Lambda-Eyde

I have yet to see anyone perform a low-temperature reaction in a solvent to produce AlCl<sub>3</sub>. You'd have to find a solvent that's inert to Al powder, chlorine gas and the trichloride. Halogenated solvents don't like metals (although I don't know how bad Al is compared to, say Na), aromatics react with chlorine in the presence of lewis acids and so on... Peach's experiment with HCl in DCM didn't turn out to be a success, either.

Under certain conditions, elemental sodium can actually be dissolved in ethers without reaction. One would think that aluminum would also be similarly unreactive at room temperature.
http://pubs.acs.org/doi/abs/10.1021/ja00197a075

Ethyl ether is not readily reactive with either sodium, or chlorine, and it is known to be able to dissolve AlCl3 as a loosely bound adduct.

Wikipedia, however, states that under some conditions aluminum tribromide can cleave ethers, forming bromoalkanes. If this is true, it suggests that it may not be possible to prepare AlBr3 or AlI3 by this method. These two lower halogens tend to be much better leaving groups than chlorine.

Aluminium tribromide reacts with carbon tetrachloride at 100 °C to form carbon tetrabromide. According to wikipedia, AlBr3 has a lower melting point (97.8 °C, below the boiling point of water) than the other halogen compounds of aluminum, so it would likely be feasible to prepare it by direct combination of the elements, simply refluxing liquid bromine with aluminum foil. Might require just a drop of mercury to begin the reaction.

[Edited on 5-1-2012 by AndersHoveland]

neptunium - 5-1-2012 at 14:08

there is a video on youtube ! i apologize i dont have the link but you can find it .
also bromine is known to react readily with Al given a few seconds it will burn in Br2 . and produce AlBr3 smokes that can be condensed..

Lambda-Eyde - 5-1-2012 at 14:15

Len has described the preparation of aluminium bromide in his book. I copied the procedure in this thread.

neptunium - 17-1-2012 at 19:17

thats it i am gonna prepare AlCl3 from its bromide...got Br2 got Al foil and easy to get Cl2...see you in a few days...

Polverone - 17-1-2012 at 20:49

Quote: Originally posted by AndersHoveland

Ethyl ether is not readily reactive with either sodium, or chlorine, and it is known to be able to dissolve AlCl3 as a loosely bound adduct.

I am inclined to instead trust Thorpe's Dictionary of Applied Chemistry:

"Chlorine acts violently upon ether, setting fire to it, and liberating carbon (Cruikshank). If the ether be kept cool by ice, and in the dark, substitution products are obtained. The Cl replaces the H atom by atom from one ethyl group first..."

AndersHoveland - 19-1-2012 at 00:11

Bromine can be dissolved in ethyl ether without immediate reaction.

from wikipedia:

Quote:

Löwig used a solution of the mineral salt saturated with chlorine and extracted the bromine with diethyl ether. After evaporation of the ether a brown liquid remained.

I thought that I found a source that mentioned anhydrous zinc chloride being prepared by passing chlorine into ethyl ether with zinc, but unfortunately I cannot find it now.

Quote:

Ethers are relatively chemically inert...

Reactions Involving Alkyl Radicals
When diethyl ether reacts with chlorine in the presence of sunlight, the main product is perchlorodiethyl ether. In the presence of sunlight all the hydrogen atoms of ether are substituted by halogen atoms. In the dark, 1,1'-dichlorodiethyl ether forms.

http://books.google.com/books?id=vj9BGa5F43wC&pg=PA1023&...

Even if the ether is immediately chlorinated by the chlorine, the reaction between the chlorine and zinc could still proceed. The text is not clear on whether the reaction in the dark is immediate.

This also might be related to the chemistry:
http://pubs.acs.org/doi/abs/10.1021/ja01364a058

Also found this:

Quote:

Anhydrous zinc-chloride may be prepared by distilling 1 pt. of zinc-filings with 2 pts of mercuric chloride, or 1 pt. zinc-oxide with 2 pts. sal-ammoniac....

So perhaps distilling NH4Cl with aluminum foil could potentially form liquid aluminum trichloride. On the other hand, this might only work for making zinc chloride, because AlCl3 is a much stronger Lewis acid. The reaction product might just be the formation of aluminum nitride on the surface.
"Reaction study of aluminium chloride with ammonia and mechanisms leading to aluminium nitride" M. Pouget and J. P. Lecompte

Aluminium chloride sublimes (turns straight from a solid to a gas) at about 180°C.

[Edited on 19-1-2012 by AndersHoveland]

Neil - 19-1-2012 at 06:00

Congratulations on your new status Mr. Anders

neptunium - 19-1-2012 at 06:27

i need a solvent that could disolve Al2Br6 (and AlCl3), i made the tribromide and would like my bromine back please...

[Edited on 19-1-2012 by neptunium]

AndersHoveland - 19-1-2012 at 12:34

Quote: Originally posted by neptunium

i need a solvent that could disolve Al2Br6 (and AlCl3),

Aluminum tribromide is soluble in benzene.
http://pubs.acs.org/doi/abs/10.1021/ja01266a505

you might see
http://pubs.acs.org/doi/abs/10.1021/ja01231a037

As for the AlCl3, it can be dissolved in ethyl ether. I have previously provided a reference for this in the thread. But the solution of AlCl3 and ether is liable to undergo a reaction if heated.

[Edited on 19-1-2012 by AndersHoveland]

AirCowPeaCock - 19-1-2012 at 12:55

NH4Cl + fine(?) Al seems like the most feasible idea to me. Or maybe dry HCl directly into pyro dark Al. Any moisture in the HCl could be removed by say Calcium carbide--but you might not have something like that lying around.

neptunium - 19-1-2012 at 14:14

nope...got a little bit of toluene to clean that Al bromide though...i m gonna try that . thanks