Sciencemadness Discussion Board

Gas azeotropes?

ave369 - 17-12-2015 at 03:20

Are there azeotropes among liquified gases? Can such a gas mixture that boils higher than any of the constituent gases exist?

And are there such azeotropes that are liquid at RT?

woelen - 17-12-2015 at 04:57

In principle I see no reason why such azeotropes could not exist. A liquefied gas is nothing else than a liquid, the only difference is that it is liquid at another temperature range than what we ordinarily call liquids.

An example of a gas azeotrope is a mix of chlorotrifluoromethane and trifluoromethane. This mixture is higher boiling than both of the compounds. The azeotropic mixture still is gaseous at room temperature though.

Another example is a mix of Cl2 and BrCl. BrCl boils at 5 C. IIRC a mixture of BrCl and Cl2 boils at higher temperature (7 C or so) and in cold waether, this azeotrope could be kept around as liquid.