Critical Temperature in a Gas

Question

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 studying it.

Answer 1

As the water is heated, the liquid becomes less dense and turns into gas (steam).  Adding more heat causes the pressure to increase, so you have the liquid becoming less dense from the increasing temperature, but the gas is becoming more dense because of pressure.

When the critical point is reached, the liquid and vapor exist in equilibrium and there is no interface (boundary) between them.

At temperatures and pressures above the critical point, the mixture is a homogeneous mixture called a supercritical fluid.  Note that a fluid can be either a gas or a liquid.

PS.  I tried to explain this considering that you are learning English.