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Author: Subject: Hand Soap + 91% IPA = Heat
Detonationology
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[*] posted on 10-11-2015 at 05:20
Hand Soap + 91% IPA = Heat


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:

FullSizeRender.jpg - 200kB

[Edited on 11-10-2015 by Detonationology]




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[*] posted on 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]




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[*] posted on 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?



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[*] posted on 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]




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