Above The Critical Temperature A Substance

The pressure required to liquify a substance vapor at its critical temperature. A molten salt is a salt heated to its melting point giving a stable liquid that conducts electricity.

10 13 Critical Temperature And Pressure Chemistry Libretexts

Two types of liquid liquid critical points are the upper critical solution temperature ucst which is the hottest point at which cooling will induce phase separation and the lower critical solution temperature lcst which is the coldest point at which heating will induce phase separation.

Above the critical temperature a substance. At the critical temperature they cannot longer be liquified. The critical temperature of a substance is the temperature at and above which vapor of the substance cannot be liquefied no matter how much pressure is applied. Above the critical temperature and pressure a substance exists as a dense fluid called a supercritical fluid which resembles a gas in that it completely fills its container but has a density comparable to that of a liquid.

Some examples are shown below. The temperature which above a substance can not exist as a liquid no matter how much pressure is applied. It can effuse through solids like a gas and dissolve materials like a liquid.

Every substance has a critical temperature. If the temperature is below critical temp and the pressure is also below its critical value then there is a possibility that we see an equilibrium between the liquid and gaseous states. A supercritical fluid scf is any substance at a temperature and pressure above its critical point where distinct liquid and gas phases do not exist.

When one of them is above their critical value it is impossible to change the state of the substance from gas to liquid by merely changing the other parameter. Every substance has a critical temperature. For instance if t t c then no matter how much you try to increase the pressure the gas will not liquefy.

Critical Point Chemistry Dictionary Glossary