| Popis: |
The kinetic theory is applied to the properties of real fluids by including the effect of molecular attraction. The observed properties of individual substances are calculated directly by pure dynamics from the attraction of their ultimate particles, thermal agitation and volume only, without the introduction of any arbitrary factors. The mutual attraction of the molecules of real substances increases their mean square velocity. Maxwell's law is modified by the introduction of a parameter λ which multiplies the most probable speed of the molecules, λ being the ratio of the most probable speed in a real fluid to that in an ideal gas. Other necessary consequences of molecular attraction are that all real gases and liquids are associated; there is at every interface an adsorbed layer which modifies the average effect of the transfer of momentum in collision, and there is a change of energy, due to variation of λ, in passing from one medium into another. These effects have been calculated. In order to apply the results, a law of force must be adopted. Edser's inverse-eighth-power law is found to hold. The method is applicable to all the physical properties of fluids and is applied, by way of example, to the equation of state of a gas and the vapour pressure and viscosity of a liquid with satisfactory results. The new theory explains the observed decrease of viscosity of liquids with temperature, without which no theory can be accepted. |
