Bedlasky
International Hazard
Posts: 1225
Registered: 15-4-2019
Location: Period 5, group 6
Member Is Offline
Mood: Volatile
|
|
Behaviour of pentavalent vanadium in concentrated HCl/HBr
Hi.
Few weeks ago I was wondering if VOCl3 can be made just from sodium vanadate and 36% HCl. It turns out that it isn't possible. However dark red
[VOCl4]- ion is formed instead. But it was very suprising that this ion on heating decomposed giving green [VOCl4]2- ion and chlorine gas. VOCl3 is
thermally stable, withstanding temperatures more than 600 °C. I really didn't expect this result. And because I had few interesting observations
during this experiment, I decided to do some experiments in 48% HBr and compare it with reactions in 36% HCl. Results are similar, but not quite the
same, because [VOBr4]- anion is even more unstable. I didn't find mention about this anion in literature, however [VOBr4]2- salts are very well
described. And I succsesfully prove that VV is present in hydrobromic acid solutions at room temperature.
https://colourchem.wordpress.com/2021/11/21/prekvapive-chova...
https://colourchem.wordpress.com/2021/11/21/surprising-behav...
[Edited on 21-11-2021 by Bedlasky]
|
|
|
DraconicAcid
International Hazard
Posts: 4298
Registered: 1-2-2013
Location: The tiniest college campus ever....
Member Is Offline
Mood: Semi-victorious.
|
|
I've been reading about vanadium in my qualitative analysis books, and boiling a solution of V(V) in hydrochloric acid dry will convert it to V(IV).
Several of the tests depend upon this.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
