arevelacao
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Registered: 4-9-2006
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vapor pressure of NH4OH
I sought a graph with pressures, temperatures and concentrations, but I didn't find anything! anybody?
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hodges
National Hazard
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I don't think "vapor pressure" is defined for NH4OH. Vapor pressure implies that as long as you have some liquid and some vapor present the pressure
depends only on temperature. For NH4OH, the pressure would be instead based on how much NH3 leaves the NH4OH as the temperature increases. The
actual pressure you end up with is going to depend not only on temperature, but also on the amount of NH4OH and the size of the space above the NH4OH.
Hodges
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unionised
International Hazard
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Contrary to popular belief NH4OH practically does not exist.
It's a myth; in my opinion, a marketing myth.
NH3 disolves in water, a vanishingly small part of it ionises.
IIRC it's Henry's law and Raoult's law you need to look up (someone who hasn't been out drinking might be able to help here).
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Flip
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The vapor pressure of ammonia can certainly be calculated for a known concentration. Just use ideal gas laws, Raoult's law, etc. There is also a
table in the CRC I believe, and you could just use Clausius-Claperon to plot the various temperatures you need based on that data.
[Edited on 9/9/06 by Flip]
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