In Liquid State Theory
In liquid state theory, the 'excluded volume' of a molecule is the volume that is inaccessible to other molecules in the system as a result of the presence of the first molecule. The excluded volume of a hard sphere is eight times its volume—however, for a two-molecule system, this volume is distributed among the two particles, giving the conventional result of four times the volume; this is an important quantity in the Van der Waals equation of state. The calculation of the excluded volume for particles with non-spherical shapes is usually difficult, since it depends on the relative orientation of the particles. The distance of closest approach of hard ellipses and their excluded area has been recently considered.
Read more about this topic: Excluded Volume
Famous quotes containing the words liquid, state and/or theory:
“While the State becomes inflated and hypertrophied in order to obtain a firm enough grip upon individuals, but without succeeding, the latter, without mutual relationships, tumble over one another like so many liquid molecules, encountering no central energy to retain, fix and organize them.”
—Emile Durkheim (1858–1917)
“George Shears ... was hanged in a barn near the store. The rope was thrown over a beam, and he was asked to walk up a ladder to save the trouble of preparing a drop for him. “Gentlemen,” he said, “I am not used to this business. Shall I jump off or slide off?” He was told to jump.”
—For the State of Montana, U.S. public relief program (1935-1943)
“Don’t confuse hypothesis and theory. The former is a possible explanation; the latter, the correct one. The establishment of theory is the very purpose of science.”
—Martin H. Fischer (1879–1962)