Detonationology - 10-11-2015 at 05:20
I had some resin on my hand that ordinary foaming hand soap would not remove. So, I poured some 91% IPA on my soapy hands. The suds dissipated and I
noticed a slight increase in temperature. I am a noob and I have no idea what would have reacted to generate heat in this situation. There is just
so many ingredients, here is a list:
[Edited on 11-10-2015 by Detonationology]
Ozone - 10-11-2015 at 08:58
I don't think it has anything to do with the soap. I think it has to do with the heat of mixing of the iPrOH and the water on your hands.
A simple (and educational) experiment would be to mix some water and iPrOH and water in an insulated cup with a thermometer or thermocouple and
observe.
Better would be to mix several by weight, calculate the mole fraction of iPrOH and see if observation agrees with the literature.
See: http://www.ddbst.com/en/EED/HE/HE%202-Propanol%3BWater.php
O3
[Edited on 10-11-2015 by Ozone]
Detonationology - 10-11-2015 at 09:08
Interesting. I was under the impression that only compounds that form ions would absorb or release heat upon dissociation. What reaction is taking
place between isopropyl alcohol and water?
Ozone - 10-11-2015 at 10:13
If I was to hazard a guess, I'd imagine that the iPrOH molecules are stabilized into a lower energy state once caged with water molecules. The
difference in energy would be measurable as heat. No dissociation of R-OH would be evident at this pH (depends on the soap, but likely weakly
alkaline--need a strong base for that, preferably non-aqueous).
See: http://sites.chem.colostate.edu/diverdi/C477/experiments/iso...
O3
[Edited on 10-11-2015 by Ozone]