Question

• For a=10^-3 and b=103.critica
pressure of a gas is given by-​

Answer 1

Answer:

Gases can be converted to liquids by compressing the gas at a suitable temperature.

Gases become more difficult to liquefy as the temperature increases because the kinetic energies of the particles that make up the gas also increase.

Microscopic view of a gas. Microscopic view of a liquid.

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.

Every substance has a critical temperature. Some examples are shown below.

substance critical temperature (oC)

NH3 132

O2 -119

CO2 31.2

H2O 374

Tubes containing water at several temperatures. Note that at or above 374oC (the critical temperature for water), only water vapor exists in the tube.

Critical Pressure

The critical pressure of a substance is the pressure required to liquefy a gas at its critical temperature. Some examples are shown below.

substance critical pressure (atm)

NH3 111.5

O2 49.7

CO2 73.0

H2O 217.7