Do gas-gas and/or liquid-liquid phase transitions exist?

[M_1]

I'm writing a short report about thermal storage using latent heat and the topic is liquid/solid phase transitions. I would however like to systematize all phase transitions in the intro and I'm curious if gas/gas and/or liquid/liquid phase transitions exist.

For gas-gas I think that the obvious answer is no, such phase transitions do not exist, but please correct me if I'm wrong.

For liquid-liquid I get the impression that such transitions are hypothesized in water, but that's all regarding such transitions. Is this correct?

Many thanks for any answers.

 

[sophiecentaur]

For gas-gas I think that the obvious answer is no, such phase transitions do not exist, but please correct me if I'm wrong.

Heat transfer without the 'expected' amount of 'sensible heat' (look it up) is actually not that uncommon. It happens when Van Der Waall's forces come into play. That's a mild version of a phase transition but doesn't involve the dramatic energy change that melting and boiling does.
But there's a tricky path if you try to to nail all Science down to the rigid descriptions we start off with.

 

[Lnewqban]

I'm writing a short report about thermal storage using latent heat and the topic is liquid/solid phase transitions. I would however like to systematize all phase transitions in the intro and I'm curious if gas/gas and/or liquid/liquid phase transitions exist.
...

Please, see:
https://en.m.wikipedia.org/wiki/Phase_(matter)

https://en.m.wikipedia.org/wiki/Phase_transition

https://en.m.wikipedia.org/wiki/Triple_point

https://en.m.wikipedia.org/wiki/Latent_heat

https://en.m.wikipedia.org/wiki/Thermal_energy_storage

 

[sophiecentaur]

Something that should be mentioned is the energy involved as some mixtures do not change state in an obvious way or at a particular temperature. Antifreeze in engine coolants spreads the temperature range of melting / solidifying over a wide range (down to -36C or more). The 'phase' state is not really definable in that range because the coolant goes more like porridge than a liquid or solid.