Critical Temperature in a Gas

Kasper_NYC

Hi,

It is supposed a metal container hermetically closed and completely filled with water; the container is supposed to have unlimited strength, so doesn’t deform under internal or external pressure.

What will be happen if we heat the water over its critical temperature (374 C degrees – 705.2 F degrees)? Will it become steam? If yes, how? Because the container is fully filled with water and this is denser than steam (that is a gas).

If doesn’t become steam (gas), will continue the water increasing its temperature over the critical temperature as we increase the temperature we apply?

Thanks a lot.

PS – I apologize for my English, I am learning it.

lsloneil

Well, according to my understanding, above the critical temperature, that is supercritical water and there will be no phase separation. Therefore, there will be only one 'fluid' phase in the region above the critical temperature. it's neither liquid nor gas, but it's still water!Since your container is fixed at constant volume, the density is also fixed. So the water (in fluid phase) will continue increasing its temperature as you increase the temperature outside, until the water molecules decompose.

That is my opinion. If anyone find errors in my words, please correct it. Thanks.

Kasper_NYC

Thanks Isloneil for your interesting answer.

Kasper_NYC

Here is a Water Diagram about it: http://www.lsbu.ac.uk/water/phase.html