Sciencemadness Discussion Board

any way to make Sb2O3 from Sb2S3?

Armus_ - 25-12-2019 at 18:06

for about 2 months i have been trying to make antimony trioxide for the synthesis of tartar emetic and ive been having lots of trouble.

first i added HCl to the Sb2Cl3 and it seemed to work for a while but for some reason when i added water to it to try to dilute it, it would precipitate this orange precipitate. later i figured out that it was dissolved hydrogen sulfide.

im wondering, what is this orange precipitate? is it some form of Sb2S3 like the red form?

also is there an easier way to make antimony trioxide than having trouble dissolving antimony trisulfide, making sure no hydrogen sulfide is in solution, adding water until SbOCl precipitates and then thermally decomposing it into Sb2O3?

Bedlasky - 26-12-2019 at 06:18

Orange Sb2S3 is hydrated, grey Sb2S3 is anhydrous, see woelen's website.

Try dissolve small amount of Sb2S3 in tartaric acid in test tube. Tartrate is strong complexing agent for antimony. Maybe you don't need Sb2O3.

[Edited on 26-12-2019 by Bedlasky]

woelen - 27-12-2019 at 10:20

You can make Sb2O3 from Sb2S3 by dissolving it in concentrated HCl and then boiling the liquid for a while to drive off all H2S. It may be necessary to filter the liquid if your SbS3 is not pure. You really need to boild for some while, to get rid of all H2S. Do the boiling outside or in a decent fume hood. H2S is quite toxic and may deaden your sense of smell.

After the boiling, dump the liquid in a lot of water to which a little ammonia is added (if your solution contains 1% NH3 or so, it is OK). You get a white precipitate, which is quite pure Sb2O3. Allow the precipitate to settle.

You may also get some algaroth (SbOCl) and if you did not boil the liquid sufficiently long, then you may get a pale yellow precipitate, which contains some Sb2S3 as well.

Armus_ - 28-12-2019 at 10:08

Quote: Originally posted by woelen  
You can make Sb2O3 from Sb2S3 by dissolving it in concentrated HCl and then boiling the liquid for a while to drive off all H2S. It may be necessary to filter the liquid if your SbS3 is not pure. You really need to boild for some while, to get rid of all H2S. Do the boiling outside or in a decent fume hood. H2S is quite toxic and may deaden your sense of smell.

After the boiling, dump the liquid in a lot of water to which a little ammonia is added (if your solution contains 1% NH3 or so, it is OK). You get a white precipitate, which is quite pure Sb2O3. Allow the precipitate to settle.

You may also get some algaroth (SbOCl) and if you did not boil the liquid sufficiently long, then you may get a pale yellow precipitate, which contains some Sb2S3 as well.


so would I have to test once in a while in water until the yellow precipitate stops?