# Liquid To solid

Name a substance that will change from liquid state to solid state on heating.

And remaining chemically unchanged? Nothing does that.

You could have your ceramics which change from a liquid structure to a solid structure, but that's with the formation of bonds on heating and all that.

tiny-tim
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eggy-weggy

QuantumPion
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And remaining chemically unchanged? Nothing does that.

You could have your ceramics which change from a liquid structure to a solid structure, but that's with the formation of bonds on heating and all that.

The first thing that came to my mind was concrete, but that is a chemical reaction and doesn't really count.

Is it possible for some sort of solid solution to have a liquid phase at a lower temperature than a solid phase? E.g. one component of the solution precipitates out with increasing temperature while the other component turns to liquid?

Mapes
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Is it possible for some sort of solid solution to have a liquid phase at a lower temperature than a solid phase?

It is possible, even for reversible transformations. It's only required that the high-temperature phase (the solid) has a higher entropy than the low-temperature phase (the liquid). As you can imagine, this is pretty unusual. I seem to remember that it's been demonstrated in some carefully designed polymer systems, though. Will look to see if I can find the details.

DaveC426913
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eggy-weggy

Changes chemically :)

Andy Resnick
eggy-weggy

Like!

Mapes
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It is possible, even for reversible transformations. It's only required that the high-temperature phase (the solid) has a higher entropy than the low-temperature phase (the liquid). As you can imagine, this is pretty unusual. I seem to remember that it's been demonstrated in some carefully designed polymer systems, though. Will look to see if I can find the details.

Ah, I found it: Plazanet et al., "Freezing on heating of liquid solutions," J Chem Phys 121:5031 p5031 (2004), discussed http://physicsworld.com/cws/article/news/20325" [Broken]. But a look at the subsequent literature indicates that the physics is still being worked out.

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QuantumPion
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Ah, I found it: Plazanet et al., "Freezing on heating of liquid solutions," J Chem Phys 121:5031 p5031 (2004), discussed http://physicsworld.com/cws/article/news/20325" [Broken]. But a look at the subsequent literature indicates that the physics is still being worked out.

Interesting, although it sounds like that is still just a chemical reaction, although notably a reversible one.

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Mapes