Highest density of water is when it’s at 4 degrees. Hence it makes sense to me that while increasing pressure, ice melting point should get lower.
However, I’ve been told that at very high pressures it’s possible to have solid ice at 79°C. How is that possible?
In: Physics
It’s not.
Here you can see the relation of pressure and temperature.
On the left you have ice, on the very right you have vapor.
https://duckduckgo.com/?q=Phasen+Diagramm+Wasser&t=fpas&ia=images&iax=images&iai=https%3A%2F%2Fwww.univie.ac.at%2Fphysikwiki%2Fimages%2Fthumb%2Ff%2Ff6%2FPhasendiagramm_Wasser.png%2F200px-Phasendiagramm_Wasser.png
> Highest density of water is when it’s at 4 degrees.
At normal atmospheric pressure, yes. At extreme pressures, this no longer holds true.
> However, I’ve been told that at very high pressures it’s possible to have solid ice at 79°C. How is that possible?
And even way above that, at least according to https://en.wikipedia.org/wiki/Phase_diagram#/media/File:Phase_diagram_of_water.svg
Latest Answers