LifeisElemental - 1-1-2015 at 14:24
Hi guys,
I hadn't planned on posting the next video I filmed here and I am not actually finished with it yet.. there's something I'm not sure how to explain in
the video.
On the addition of HCl to aniline a significant amount of a dense white smoke was evolved as seen in the video below. Is this ammonium chloride? How
can this form from aniline? Am I losing some of my phenylammonium chloride?
I'm sure this is something trivial or obvious but it would be great to know it so I can pass it on to viewers in the final video.
https://www.youtube.com/watch?v=kTPefB624wI&feature=youtu.be
The moment happens about 20 seconds in FYI.
Thanks!
DraconicAcid - 1-1-2015 at 14:29
A small amount of aniline vapour in the air will react with the fumes of HCl to give solid phenylammonium chloride.
ParadoxChem126 - 1-1-2015 at 14:37
I have witnessed the same white fumes in the synthesis of chlorobenzene detailed here:
http://www.sciencemadness.org/talk/viewthread.php?tid=32851
I'm fairly certain that it is phenylammonium chloride. Aniline vapor would react with hydrogen chloride much like the way NH3 reacts with
HCl. This leads me to believe that the white smoke is due to the formation of phenylammonium chloride.
However, it should not significantly affect your yield because only negligible amounts are lost as fumes.
[Edited on 1-1-2015 by ParadoxChem126]
Metacelsus - 1-1-2015 at 15:01
O-toluidine also behaves this way, from personal experience.
S.C. Wack - 1-1-2015 at 15:13
I'd assume that it's HCl vaporized by the heat of neutralization. It happens with bases much less volatile than aniline.
zed - 9-1-2015 at 16:38
Yup. Seems like a version of the old UC Berkeley chemical espionage scheme. Wherein enterprising students graded on a CURVE, improved their own
grades at the expense of their classmates. A few drops of Ammonia in a competitors locker, followed by a few drops of ammonia, and "poof" ammonium
chloride smoke coats all of the glassware. Loss of a whole lab period. Gotta wash and dry all of your glassware before you can do your next
experiment.
zed - 7-6-2015 at 13:05
Whoops! Meant to say:
Yup. Seems like a version of the old UC Berkeley chemical espionage scheme. Wherein enterprising students graded on a CURVE, improved their own grades
at the expense of their classmates. Instill a few drops of liquid Ammonium Hydroxide into a competitors locker, followed by a few drops of
Hydrochloric acid, and "poof" ammonium chloride "smoke" gradually coats all of the glassware. Loss of a whole lab period. Gotta wash and dry all of
your glassware before you can do your next experiment.