Sciencemadness Discussion Board - Making Antimony Trichloride

Making Antimony Trichloride

dann2 - 28-11-2007 at 19:56

Hello,

Need to make Antimony Trichloride.
Asked in here before (and got good advice too) but my problem is I want to use dilute HCl acid (12%). Will that do the job (together with Hydrogen Peroxide) or will I get Antimony Oxide forming due to the extra water.

Cheers,
Dann2

Fleaker - 28-11-2007 at 20:08

It won't do the job. It will hydrolyze fairly rapidly.

Ozone - 28-11-2007 at 21:40

Maybe this will be of interest to you:

http://www.sciencemadness.org/talk/viewthread.php?tid=9176&a...

I'd go into this a bit more, but I have my Oral (quals) exam tomorrow.

Passed the written, praying not to get hosed,

O3

Sauron - 28-11-2007 at 21:51

I believe this is made by direct union of the elements. See Brauer.

I can think of other ways but they are all more expensive.

Such as Sb2O3 and oxalyl chloride.

not_important - 28-11-2007 at 23:21

The old traditional method

Quote:

Antimony Trichloride, Antimonous Chloride, SbCl3.
Preparation.
By dissolving antimony oxide or antimony sulphide in hydrochloric acid: Sb2S3+6HCl=2SbCl3+3H2S. This is then distilled, when first H2S, if the sulfide is used, then the excess of hydrochloric acid, and finally the antimony trichloride pass over.
Properties. Colorless, fuming, crystalline, caustic, soft masses. (hence formerly called butter of antimony), which melt at 73° and boil at 223° and which absorb water from the air and deliquesce.
Antimony chloride is soluble in hydrochloric acid; if this solution or solid antimony chloride is treated with considerable water, a white crystalline precipitate of
Antimony oyxchloride, SbOCl, is obtained. This was formerly called Algarot powder. It contains various amounts of antimony trioxide according to the method of preparation:
2SbCl,+ 3H20 = Sb2O3 + 6HC1 ;
SbCl3+ H20 = SbOCl+2HCl.

The sulfide was commonly used as the crude form was obtained directly from the ore, the oxides are much more common today. The hydrochloric acid needs to be pretty strong. A more modern preparation has you concentrate the solution, add concentrate (35%) hydrochloric acid, and distill that. The HCl removes remaining water as the 20% azeotrope, the excess HCl keeps the SbCl3 from hydrolyzing.

[Edited on 29-11-2007 by not_important]

dann2 - 29-11-2007 at 15:44

Hello,

I made SbCl3 before using Antimony metal + 35%HCl + adding H2O2 every now. Ended up with a yeelow viscous liqued. Did not seperaet the stuff out as a solid.
Just wondering if 12% (or 20%, easy to get by distilling 12%) would do instead of 35%.

Good luck with exam!!!!!!!

Dann2

Rosco Bodine - 29-11-2007 at 18:20

That viscous liquid could very well be an inorganic polymer , formed from some of the SbCl5 being reduced
by the Sb metal to SbCl3 and then further combining with
hydrolysis products of the SbCl5 . If tin was present in system also a substituted co-polymer could also form .
But a deficiency of HCl , or loss of HCl upon continued heating with some attendant hydrolysis of the higher oxidation state chlorides is *required* for the formation of such inorganic polymers . They will be colored and they will be syrupy . If dried out completely , an amorphous powder should result rather than a crystallization .
and the dried product should resuspend and reconstitute
when added to water again , behaving something like
gelatin instead of a salt , as it has a colloidal form .
It may be resuspended in solvents other than water also .

Sauron - 29-11-2007 at 23:02

Not sure what you get from antimony and dil HCl but it is not SbCl3.

Sb and Cl2 is what you need.

Any route to SbCl3 from HCl needs concentrated HCl and the oxide or sulfide of antimony.

not_important - 30-11-2007 at 00:10

Constant boiling HCl will keep SbCl3 as the chloride, if making it from the sulfide or oxide you need a fir large excess. However that will only give you a solution, if you want pure SbCl3 you need to use concentrate hydrochloride acid in sufficient excess that all the water formed will be removed as the constant boiling acid while still leaving some free HCl in the mixture. The concentrated acid need not be really pure, as the distillation of the SbCl3 will leave behind the most common contaminates.

If you use Sb metal and Cl2 either stop the reaction before all the metal is gone, or add a little of the metal to the mix after gassing is stopped to remove any SbCl5 formed.

Me, I'd rather work with con HCl than Cl2, as I don't have a big enough electrolysis rig that will withstand Cl2, and if I'm making Cl2 chemically I'm using con HCl anyway.

Rosco Bodine - 30-11-2007 at 02:16

Antimony pentoxide is produced from aqueous H2O2 and powdered antimony metal . With HCl added , the mixed valency inorganic polymer seems inevitable to be the product .

Attachment: US4348301 Colloidal_sols_of_antimony via Hydrogen Peroxide.pdf (250kB)
This file has been downloaded 732 times

dann2 - 30-11-2007 at 15:00

Hello,

Looks like I was using a mixed valency polymer as my Antimony source all along (DTOing).

as I made my 'SbCl3' from conc. HCl and H2O2.

Dann3

Rosco Bodine - 30-11-2007 at 17:15

Yeah but when you later added more HCl you probably depolymerized it . A partial hydrolysis has to be allowed .
You have to partially reverse the process you used to first get everything dissolved . Anyway working with the Sn and Sb separately , you would likely not have gotten the
co-polymer where you have both Sn and Sb in the same chain . But it still would've probably been better as a mixture than what you got adding HCl after mixing the
syrupy materials . I'll bet the mixture thinned out quite a bit when the HCl hit the mixture .

dann2 - 30-11-2007 at 19:35

Hello,

I was using SnCl4:5H2O (out of a jar) + my 'Antimony Trichloride' viscous liquid.

Dann2

Rosco Bodine - 30-11-2007 at 20:14

And you added HCl to it , wherever it came from , right ?

And the change in pH made it get a whole lot thinner
than it would seem like it should be thinned by the little amount of liquid as HCl you added , ....correct ????

[Edited on 30-11-2007 by Rosco Bodine]

Eclectic - 30-11-2007 at 20:49

If you powder the Sb, it will dissolve in a hot concentrated SnCl4 solution, forming SbCl3 and some SnCl2.

Rosco Bodine - 30-11-2007 at 21:30

Maybe should post that "inorganic polymer" patent
as a thread unto itself .

But then anybody could say there's just too many irons in the fire .......only they're all titanium

dann2 - 1-12-2007 at 15:02

Hello,

@Rosco
Not too sure what exactly you are asking.
I never added HCl directly to my viscous SbClx solution since I have no need to.
To make up my DTO precursor solution I proeeded as follows:

Take 4 grams of SnCl4:5H2O (solid from jar).
Add to 6 grams IPA alcohol. It dissolves OK.
Add 1.5 grams 32% HCl. (good stuff, it's homemade).(approx.) 0.5 grams of my viscous SbClx solution. (The solution contains 41% Sb).

Adding Sb directly to SnCl4 solution sounds good! though any time I tried to make a DTO using 50/50 (2 + 2 grams I used) of SnCl2:2H2O + SnCl4:5H2O (both out of a jar) I got very patchy black and white deposits. Perhaps the small amount of SnCl2 formed will give me patchy bad coates again. Will try it out if I get a chance. Have to get more Sb (dissolved for precursor solution) some way or other.

The only reason I wanted (still would like) to use SnCl2:2H2O is that it makes the whole process OTC. Since I managed to get my hands on SnCl4:5H2O, I guess perhaps its time I moved on. NONE of the patents or processes that I have seen used Sn(ii) in their examples, they ALL have used Sn(iv).

Dann2

Rosco Bodine - 1-12-2007 at 15:38

When you use H2O2 plus HCl , to dissolve the Sn metal alloy , you are going to have *plenty* of the SnCl4 as the product in the acid rich mixture that is your clear solution . The same applies for the SbCl5 . You don't have to do anything *extra* to get your hands on it
because that's what you have already . What you then need to do is to step the mixture back down to a mixed
valency mixture by leaving it in contact with some of the metal . Then boiling off the excess acid as well as some acid which will be lost by hydrolysis , you cause *partial* hydrolysis to occur , at which point you have the three
different materials present in the mixture for formation of the inorganic polymer to occur .

dann2 - 1-12-2007 at 21:16

Hello,

Will make myself a Tin Antimony Alloy (10%??)(I have no solder) dissolve and go from there. When you say 'leave in contact with the metal' do you mean both metals. ie some of the alloy filed to fine powder?

Dann2

Rosco Bodine - 2-12-2007 at 02:06

You don't have to make the alloy just use the separate metals . 95/5 solder alloy is 95% Sn and 5% Sb . Right , react in contact with both metals , mixed or alloyed . Powdered metals will simply react more quickly .

dann2 - 2-12-2007 at 05:27

Hello,

The reason I melt the metals together is that it is a good way to effectively get finely divided Sb which is the hardest to get to dissolve.

Dann2

dann2 - 13-12-2007 at 12:04

Hello,

Made a batch of SbClx by adding 0.125 mole Antimony Oxide (ceramic grade) to 32% HCl and refluxing. A small amount of insoluble ppt was filered off and they I started to distill off excess acid and water.
I collected what came off between about 108.5 and 110C. Then temp. increased to 115C. Collected what came accross between 110 to 115.
Stoped distilling.
There is Antimony in what came accross between 110 an 115C, as seen by a ppt when a drop of it is put into water. I added this (110 to 115C) fraction back into distilling flask.
There is no ppt when a drop of the 108.5 to 110C fraction is droped into water.
Is this a sensitive test for Sb?
Most of my SbClx is still in the distilling flask btw, yellow solution.
Does anyone know of a test for Antimony that is simple
and that I can use to see of there is Antimony is the 108.5 TO 110C fraction.
I need to know the total amount of Sb I have left in the distilling flask.
Not looking for solid SbClx the solution is fine.

TIA,
Dann2

[Edited on 13-12-2007 by dann2]

Rosco Bodine - 13-12-2007 at 13:15

Gmelin circa 1868 says that in the absence of free HCl ,
turbidity is observed on deliquescence ( dilution H2O ) .

The whole chapter is a couple of megs , so I excerpted
some that may be of interest .

Attachment: Antimony chapter excerpts Gmelin 1868 .pdf (485kB)
This file has been downloaded 772 times

dann2 - 13-12-2007 at 22:52

Hello,

Thanks Roscoe, I done the following:
Written in lecture mode!!!!!!!!

36.4 grams (0.125 mole) of ceramic grade Antimony Trioxide was placed into a beaker and 114 grams 32% Hydrochloric acid was added. 
Would have used higher concentration acid if I hade it.
The suspension was heated to dissolve the Oxide. A small insoluble amount was filtered out. The solution was then boiled to drive off the excess
HCl and water. The water will boil off first and then the temperture will rise to about 108C where an azetope of water and HCl(20%) will boil off. Add
some concentrated HCl acid if there is any sign of a white ppt forming. 
When temperature reaches 109.5C or so stop boiling/distilling. Weigh the (approx. 54cc) yellow fluid and calculate the % Sb contained in it. This solution of SbClx
is suitable for making DTO precursor. The above is best done in a distillation apparatus if you have access to one. 
I obtained 52cc of solution weighing 94.3 grams from 36.4 grams Sb Oxide and 114cc 32% Hyrdochloric acid. One portion of approx. 20cc
acid was added when boiling/distilling off the water + acid.
That equated to a final yellow solution containing 2x(0.125) mole Sb = 30.44grams. Taking 30 grams only (to allow for Sb left behind in flask) this equated to the solution containing 31.8% Sb.

Dann2

not_important - 14-12-2007 at 02:38

Pure SbCl3 is colourless. A yellow colour is often due to iron, or if made from Sb and Cl2 to an excess of chlorine.

Adding sodium acetate solution to a clear solution of SbCl3 + HCl will result in turbidity forming as the HCl is converted to NaCl and acetic acid. Using 'cream of tartar' instead of sodium acetate results in the solution remaining clear; tartaric or citric acid will redissolve the basic antimony salts formed on dilution or neutralising,

H2S or an alkali sulfide will precipitate the orange-red sulfides, thiosulfate gives a yellow changing to orange ppt, while KI will give yellow SbI3. If the solution is too strongly acid those reaction will not happen, again NaOAc or cream of tartar can be added as well to bring the pH to around 3-4.

Rosco Bodine - 14-12-2007 at 08:08

Don't convert all of your initial lower valency material
to the higher valency material . Save out half or at least part of the stuff that you have made first as the lower oxidation state . You will find it useful later for a Pytlewski inspired experiment at wettest stickiest syrup making

dann2 - 14-12-2007 at 12:53

Hello,

Perhaps the Antimony Oxide (ceramic grade) contains Iron.

If it workes for Doped Tin Oxide I do not mind but it would be nice to have no unknowns in the stuff.

Regarding its valency, I don't really mind what the valency is. Similar procedure worked for Antimony Metal + HCl for the DTO so hopefully this will too.
Metal + HCl resulted in yellow liqued too. The HCl is hardware store (yellow) stuff that has been distilled giving clear HCl.

Dann2

Rosco Bodine - 14-12-2007 at 13:33

This is more concerning tin , but since it is relevant
concerning the destined use , here goes .

The baking of the Sn oxide in air leads to mostly +IV valency material ultimately , but some residual +II material may actually provide doping of a sort all by itself . So it very well may be counterproductive to drive the reaction all the way to the +IV valency material since the electrical conductivity of the resulting *pure* SnO2 is poor . It may be better to have an incompletely oxidized precusor mixture . One sure way of getting that is to mix the lower with the higher , in which case a mixed valency polymer results . On baking then a
mixed oxide is likely to result , having a better conductivity
already by virtue of its own composition .

As for dopant materials , there are many besides the Sb ,
and fluorine is perhaps the very best . It can be added
as ammonium fluoride or as dilute HF or as
stannous fluoride . This would likely be good for any contemplated scheme where you might be trying to have
a catalytically doped SnO2 coating as a possible working anode for perchlorate , as F is a known catalyst for perchlorate (with PbO2) . Whether the Sb is also , I'm not sure , and some of these catalysts act as such only in combination with something else specific . So alone
or in other combinations it may be a different story .

[Edited on 14-12-2007 by Rosco Bodine]

dann2 - 15-12-2007 at 12:40

Hello,

As suggested elsewhere to me my Electic I addes some SnCl4 + water (+HCl) and some Sb chips (and heated) to see if Sb dissolves.
It did not dissolve when cold (9 days).
Heated and the Sb dissolved in about 8 hours but there is some black stuff contained in the solution.
Anyone know what it may be.

Sb came from an ebay element collector on ebay and is 'pure'.

Dann2