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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: R717NOVAH on September 12, 2020, 10:46:12 PM

Title: How does Ammonia achieve -70°C in atmospheric pressure?
Post by: R717NOVAH on September 12, 2020, 10:46:12 PM

I can witness liquid NH3 achieving sub 'boiling point' temperatures by simpling removing a thermocouple from a container of liquid, typically around -40 to -60°C.

I see that as the Ammonia evaporates energy is lost from the liquid droplets and I would imagine a loss in density.

With the exception of mathematical explanations from the works of Geoffrey D. Kaiser & Richard F. Griffiths, I am yet to find an explanation that hits home of how this occurs other than terms like entrained air and adiabatic volumetric expansion, partial pressures etc. I would like to find some visualisation of what is exactly going on in this process.

Title: Re: How does Ammonia achieve -70°C in atmospheric pressure?
Post by: sjb on September 13, 2020, 02:09:53 AM

No need to cross-post. Locked here.