Sciencemadness Discussion Board

Preparation of Bismuth chloride

Waffles SS - 24-7-2016 at 09:10
Quote:

Bismuth chloride can be synthesized directly by passing chlorine over bismuth.

2 Bi + 3 Cl2 → 2 BiCl3

or by dissolving bismuth metal in aqua regia, evaporating the mixture to give BiCl3.2H2O, which can be distilled to form the anhydrous trichloride.

Alternatively, it may be prepared by adding hydrochloric acid to bismuth oxide and evaporating the solution.

Bi2O3 + 6 HCl → 2 BiCl3 + 3 H2O

Also, the compound can be prepared by dissolving bismuth in concentrated nitric acid and then adding solid sodium chloride into this solution.

Bi + 6 HNO3 → Bi(NO3)3 + 3 H2O + 3 NO2
Bi(NO3)3 + 3 NaCl → BiCl3 + 3 NaNO3

https://en.wikipedia.org/wiki/Bismuth_chloride


I tried to make it by adding NaCl to Bi(NO3)3 solution in Nitric acid and got nothing.
Just color of Nitric acid changed from clear to yellow(i used 1gr Bi(NO3) 3 ,5 ml 65%Nitric acid and 1 gr NaCl)

Someone has experience on making BiCl3?


[Edited on 24-7-2016 by Waffles SS]

Trevor9424 - 24-7-2016 at 10:18

You could instead buy some pepto-bismol tablets, react them with hydrochloric acid to make bismuth chloride and salicylic acid, filter away the salicylic acid and any leftover pesto-bismol, and then try to recrystalize the bismuth chloride.

Texium - 24-7-2016 at 10:32

Bismuth chloride is not the friendliest compound to work with. It will reversibly react with water to form bismuth oxychloride (BiOCl), so it has to be recrystallized from fairly concentrated hydrochloric acid. If the solution is not acidic enough, a white precipitate of the oxychloride will form. The way that you attempted to make it seems rather odd and unreliable.

I made some once by dissolving bismuth metal in a large excess of concentrated hydrochloric acid with some 3% hydrogen peroxide added. This was evaporated slowly over a few days, with more hydrochloric acid added as needed. It was only a couple of grams.

Waffles SS - 24-7-2016 at 10:38

Bismuth Chloride hydrolysis to Oxychlorid in aqueous solution and i think this is not possible to use Hydrochloric acid for making it.
Quote:

BiOCl is formed during the reaction of bismuth chloride with water, i.e. the hydrolysis:

BiCl3 + H2O → BiOCl + 2 HCl

https://en.wikipedia.org/wiki/Bismuth_oxychloride



I think reaction of bismuth metal with Hydrogen chloride in or without solvent(like acetic acid) should prevent hydrolysis
Quote:

Eberius, E.; Kowalski, W.Z. Erzbergbau Metallhuettenwesen, 1954 , vol. 7, p. 339 - 343



Also i think reaction of Bismuth metal or oxide with Thionyl chloride should be possible route for synthesis BiCl3
Quote:

North, H. B.; Hageman, A. M.Journal of the American Chemical Society, 1913 , vol. 35, p. 355 - 355



[Edited on 24-7-2016 by Waffles SS]

Texium - 24-7-2016 at 10:43

Quote: Originally posted by Waffles SS  
Quote:

BiOCl is formed during the reaction of bismuth chloride with water, i.e. the hydrolysis:

BiCl3 + H2O → BiOCl + 2 HCl

https://en.wikipedia.org/wiki/Bismuth_oxychloride
Yes... I just said exactly that in my previous post. However, it is certainly possible to make it using hydrochloric acid as long as the concentration of the acid is kept high while it is crystallizing. The hydrolysis is completely reversible. I can confirm all of this from personal experience and the fact that I have a vial of bismuth chloride crystals sitting here which were prepared using the method that I described.

Waffles SS - 24-7-2016 at 10:49

Thanks @zts16,

Can you explain more your method? (ratio and temp)

Texium - 24-7-2016 at 11:35

Unfortunately I did not write down the amounts that I used (it was over a year ago, before I kept a real lab notebook), but it was done at room temperature. I will try it again at some point and actually write down the procedure and maybe even make a video. This probably won't be anytime soon though.

Mabus - 25-7-2016 at 16:08

I worked with the stuff at my uni. It hydrolyzes very fast in air, in about 1 minute it's all wet. It's also damn corrosive. I used to purify it by subliming it under vacuum and condensing it on a cold finger. From there I transferred in a Schlenk vial, under argon.
I know it's somewhat soluble in diethyl ether, can't remember the exact value, something around 4-5 g/100ml (I think, don't take my word for it). If you want to avoid water, you could bubble dry hydrogen chloride gas through ether + bismuth metal with an inverted funnel (the dissolution of the gas is pretty exothermic, use cooling) and then recrystallize it from ether in dry air.
But unless you want high purity, the good old recrystallization from acid should be enough.

Waffles SS - 26-7-2016 at 06:35

Today i tried to make BiCl3 from Bismuth metal .

I used 0.1 mol(20.9gr) Bismuth metal , 0.3mol(~100gr) HCl(37%) , 50gr H2O2 35%
The color of mixture changed from clear to green after adding all material.small bubbles of oxygen released and after 3 hours most of metal still exist.

It seems i need exact procedure for making BiCl3 by this method


[Edited on 26-7-2016 by Waffles SS]