Chemgineer
Hazard to Others
Posts: 206
Registered: 25-5-2021
Member Is Offline
|
|
Antimony (iii) oxide and hcl.
I am confused, I have some antimony (iii) oxide and I expected that on mixing with hcl it would release oxygen, neutralise the acid and end up as a
solution of antimony (iii) chloride.
Is this a slow reaction that needs time and heating or am I missing something?
I'm not seeing a fizzing like you would with a carbonate and i'm collecting white precipitate at the bottom of my beaker, Although I think less than
the oxide i've added.
|
|
|
B(a)P
International Hazard
Posts: 1137
Registered: 29-9-2019
Member Is Offline
Mood: Festive
|
|
Quote: Originally posted by Chemgineer  | I am confused, I have some antimony (iii) oxide and I expected that on mixing with hcl it would release oxygen, neutralise the acid and end up as a
solution of antimony (iii) chloride.
Is this a slow reaction that needs time and heating or am I missing something?
I'm not seeing a fizzing like you would with a carbonate and i'm collecting white precipitate at the bottom of my beaker, Although I think less than
the oxide i've added. |
There is some discussion in this thread.
https://www.sciencemadness.org/talk/viewthread.php?tid=9551
|
|
|
bnull
Hazard to Others
Posts: 300
Registered: 15-1-2024
Location: Between the Atlantic and the Pacific Ocean
Member Is Online
Mood: Sleepy (again)
|
|
| Quote: | I have some antimony (iii) oxide and I expected that on mixing with hcl it would release oxygen, neutralise the acid and end up as a solution of
antimony (iii) chloride.
Is this a slow reaction that needs time and heating or am I missing something?
I'm not seeing a fizzing like you would with a carbonate |
It doesn't release oxygen upon dissolution in acids. If it were to, then it would have to reduce its oxidation number from +3 to something else (say,
+2). It is not a peroxide either, and again no oxygen release. The only product besides SbCl3 is water, hence no fizzing.
| Quote: | | and i'm collecting white precipitate at the bottom of my beaker, Although I think less than the oxide i've added. |
It may be one of the oxychlorides. Your antimony trichloride may be hydrolising, although I wouldn't expect it to happen immediately. Are you using
concentrated acid?
Edit:  Ninja attack...
[Edited on 6-8-2024 by bnull]
Quod scripsi, scripsi.
B. N. Ull
P.S.: Did you know that we have a Library?
|
|
|
Chemgineer
Hazard to Others
Posts: 206
Registered: 25-5-2021
Member Is Offline
|
|
| Quote: Originally posted by bnull | | Quote: | I have some antimony (iii) oxide and I expected that on mixing with hcl it would release oxygen, neutralise the acid and end up as a solution of
antimony (iii) chloride.
Is this a slow reaction that needs time and heating or am I missing something?
I'm not seeing a fizzing like you would with a carbonate |
It doesn't release oxygen upon dissolution in acids. If it were to, then it would have to reduce its oxidation number from +3 to something else (say,
+2). It is not a peroxide either, and again no oxygen release. The only product besides SbCl3 is water, hence no fizzing.
| Quote: | | and i'm collecting white precipitate at the bottom of my beaker, Although I think less than the oxide i've added. |
It may be one of the oxychlorides. Your antimony trichloride may be hydrolising, although I wouldn't expect it to happen immediately. Are you using
concentrated acid?
Edit: Ninja attack...
[Edited on 6-8-2024 by bnull] |
I am using 20% hcl.
[Edited on 6-8-2024 by Chemgineer]
|
|
|
Precipitates
Hazard to Self
Posts: 69
Registered: 4-12-2023
Location: SE Asia
Member Is Offline
Mood: Acid hungry
|
|
May still not be enough. I'm sure I've had trouble (or at least noticed) oxychlorides or oxynitrates in the past (can't remember the compound though,
maybe copper), in pretty strongly acidic solutions.
20% HCl is the starting concentration, but of course upon antimony (III) oxide addition this will rapidly reduce.
Antimony trichloride will convert to antimony oxychloride in the smallest amount of water.
In any case, after completely adding the antimony (III) oxide to a large excess of the acid, I'd try heating the solution to concentrate the remaining
acid and hopefully dissolve the precipitate*. Once a clear solution has been obtained, the solution can be gently heated to dryness. Given how
sensitive this compound is to moisture, it will need to be stored straight away in an air-tight container.
Sciencemadness wiki has a nice summary of probably the best routes to pure antimony (III) trichloride.
*May need to add even more acid.
|
|
|
woelen
Super Administrator
Posts: 7988
Registered: 20-8-2005
Location: Netherlands
Member Is Offline
Mood: interested
|
|
Antinomy(III) oxide, Sb2O3, dissolves in excess concentrated hydrochloric acid quite easily, giving a clear and colorless solution. However, even
moderately concentrated acid (e.g. 20%) already has quite some difficulty dissolving Sb2O3. With 10% HCl, only very dilute solutions can be obtained.
If you prepare a solution of Sb2O3 in conc. HCl (at least 30% by weight), then you can dissolve a few hundreds of mg (a nice heap of solid on the tip
of a big screw driver) in 5 ml of acid or so. On addition of some water, the clear liquid becomes turbid and a white precipitate is formed. SbCl3 very
very easily hydrolysed in water, to SbOCl and HCl, or even back to Sb2O3 (at high dilution, or at somewhat alkaline conditions).
[Edited on 8-8-24 by woelen]
|
|
|
chloric1
International Hazard
Posts: 1087
Registered: 8-10-2003
Location: GroupVII of the periodic table
Member Is Offline
Mood: Stoichiometrically Balanced
|
|
| Quote: Originally posted by woelen | Antinomy(III) oxide, Sb2O3, dissolves in excess concentrated hydrochloric acid quite easily, giving a clear and colorless solution. However, even
moderately concentrated acid (e.g. 20%) already has quite some difficulty dissolving Sb2O3. With 10% HCl, only very dilute solutions can be obtained.
If you prepare a solution of Sb2O3 in conc. HCl (at least 30% by weight), then you can dissolve a few hundreds of mg (a nice heap of solid on the tip
of a big screw driver) in 5 ml of acid or so. On addition of some water, the clear liquid becomes turbid and a white precipitate is formed. SbCl3 very
very easily hydrolysed in water, to SbOCl and HCl, or even back to Sb2O3 (at high dilution, or at somewhat alkaline conditions).
[Edited on 8-8-24 by woelen] |
Wow thanks so comprehensive. I love getting lost in your chemistry website! About the only use I’d have for antimony would be part of a metal
patina formula. I’m stocking up preparing some nitrates and acetates. Copper acetate has a REALLY low solubility BTW
Fellow molecular manipulator
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
