①pVm increases monotonically with p

②As p increases, pVm initially remains unchanged and then increases.

③As p increases, pVm first decreases and then increases.

Internal pressure: a/Vm^2

nRT=(p n^2/V^2)（V-nb）

pVm=RT(1 Bp Cp^2 Dp^3...) or pVm=RT（1 B’/Vm C’/Vm^2 D’/Vm^3...)

R-K equation B-W-R equation Besselot equation

Contrast pressure

Contrast volume

Compare temperature

Comparison parameters

Two-parameter generalized compression factor graph

Given p and T, find Vm

Given T and Vm, find p

Given p and Vm, find Z and T

At a certain temperature, when the evaporation rate of liquid is equal to the condensation rate of gas , a state in which the macroscopic state does not change with time is called a gas-liquid equilibrium state

The vapor pressure at this time is the saturated vapor pressure of the liquid

Critical pressure Pc

Critical molar volume Vm,c

critical temperature Tc

collectively referred to as material critical parameters

When T=Tc, the horizontal line shrinks to one point, which is the critical point.

Supercritical fluid: Substance at a temperature and pressure slightly above the critical state, it is neither a gas nor a liquid in the general sense.

Mole fraction x or y: the ratio of the amount of a substance to the total amount of the mixture

Mass fraction wB: the ratio of the mass of the substance to the mass of the mixture

Volume fraction φB: the ratio of the volume of B before mixing to the sum of the volumes of all pure components before mixing

Partial Pressure: The contribution of each gas to the total pressure

Law: The total pressure of a mixed gas is equal to the total pressure of each component present alone in the mixture. The sum of the pressures generated at the temperature and volume of the combined gas

Partial volume: indicates that the volume of a mixture is additive

Law: The total volume of a low-pressure gas mixture is equal to its components The sum of occupied volumes under the same temperature and total pressure p

Molar gas constant R=8.314472Pa•m^3•mol^-1•K^-1

1662 Boyle’s Law (Boyle R) pV = constant (n, T are certain)

1808 Gay-Lussac's law (Gay J-LIssac J) V/T=constant (n, p are certain)

1869 Avogadro’s law (Avogadro A) V/n = constant (T and p are certain)

pV=nRT

F=-dE(r)/dr(F is the intermolecular interaction force, E is the interaction potential energy, r is the intermolecular distance)

Lennard-Jones theory: The mutual attraction potential energy between two molecules is inversely proportional to the sixth power of the distance r

Characteristics of an ideal gas: ① No interaction between molecules ② The molecules themselves do not occupy volume

① Gas is composed of a large number of molecules. Gas molecules can be regarded as A particle or hard sphere without volume

②Gas molecules are in constant and irregular motion

③Except for the moment of collision, there is no interaction between gas molecules

④The collisions between gas molecules and between gas molecules against the wall are elastic collisions.

pV=2/3nLεt→The pressure of an ideal gas depends on the unit volume The number of molecules and the average translational kinetic energy of the molecules

Boltzmann's constant k=R/L=1.381×10^-23J•K^-1