Search results
Results From The WOW.Com Content Network
One way to write the van der Waals equation is: [8] [9] [10] = where is pressure, is temperature, and = / is molar volume. In addition is the Avogadro constant, is the volume, and is the number of molecules (the ratio / is a physical quantity with base unit mole (symbol mol) in the SI).
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; [2] this is an important quantity in the Van der Waals equation of state. The calculation of the excluded volume for particles with non ...
The van der Waals equation predicts that at low temperatures liquids sustain enormous tension---a fact that has led some authors to take the equation lightly. In recent years measurements have been made that reveal this to be entirely correct. [43]
Proposed in 1873, the van der Waals equation of state was one of the first to perform markedly better than the ideal gas law. In this equation, usually is called the attraction parameter and the repulsion parameter (or the effective molecular volume). While the equation is definitely superior to the ideal gas law and does predict the formation ...
For a gas obeying the van der Waals equation, the explicit formula for the fugacity coefficient is = (()) This formula is based on the molar volume. Since the pressure and the molar volume are related through the equation of state; a typical procedure would be to choose a volume, calculate the corresponding pressure, and then evaluate ...
DLVO theory is the combined effect of van der Waals and double layer force. For the derivation, different conditions must be taken into account and different equations can be obtained. [13] But some useful assumptions can effectively simplify the process, which are suitable for ordinary conditions.
The following table lists the Van der Waals constants (from the Van der Waals equation) for a number of common gases and volatile liquids. [ 1 ] To convert from L 2 b a r / m o l 2 {\displaystyle \mathrm {L^{2}bar/mol^{2}} } to L 2 k P a / m o l 2 {\displaystyle \mathrm {L^{2}kPa/mol^{2}} } , multiply by 100.
J. M. Smith, H.C.Van Ness, M. M. Abbot Introduction to Chemical Engineering Thermodynamics 2000, McGraw-Hill 6TH edition ISBN 0-07-240296-2 Robert Perry, Don W. Green Perry's Chemical Engineers' Handbook 2007 McGraw-Hill 8TH edition ISBN 0-07-142294-3