Echoing the marvelous question of a material that freezes when heat is added at constant pressure, I am wondering whether there is a material that would boil when heat is removed at constant pressure. Any idea?
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You need to be careful to distinguish between cooling (i.e. reducing the temperature. Notice this was the wording of the previous question) and removing heat (i.e. transferring energy out of the material). At phase transitions materials can give off or absorb latent heat, so it is possible, in principle, here for you to both remove heat and increase the temperature (or vice versa) as the latent heat accounts for both increasing the internal energy of the medium and depositing energy in the surroundings (although this behaviour is unusual). – By Symmetry May 17 '18 at 19:23
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@BySymmetry - Do you know of any cases where the latent heat of a transition can actually increase the temperature as heat is being removed from a material? Consider the liquid water-to-ice transition. Yes, as heat is removed from liquid water the latent heat of the transition will halt the temperature at T=0 ˚C until all of the water is transformed to ice, but the latent heat doesn't ever increase the temperature at any time. It merely arrests the drop in temperature at 0 ˚C until the transition is complete. – May 17 '18 at 19:30
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For a material to boil as heat is removed (or temperature is decreased), the phase line between the liquid and gaseous phases on a pressure-temperature plot would have to be negative in some region. By the Clausius–Clapeyron equation, I doubt that that is possible for a liquid-gas transition since the latent heat and change in volume across such a transition are always going to be positive for a liquid-gas transition. So I'm going to guess that no such material exists. – May 17 '18 at 19:53