London constant

Assume that the intermolecular attraction in this case is dominated by the London interaction, that is, = -Cr 6, for which C is the London parameter (Equation (25)). Estimate the London constant from the equation-of-state data and compare it with the coefficient from Equation (25). The polarizability [cco tteo)] for CH4 is 2.6 10-3° m3. The ionization energy / is 2.0185 10 18J (Israelachvili 1991, Chapter6 and Table 6.1). 

For two atoms i and j with London constants and Pj, the interaction constant Pij is given by... 

The parameter that characterizes dispersion interactions is the London constant, aL,... 

The attractive energy (E) of all types of interactions between dipoles is proportional to r, where r is the distance between the centres of interacting molecules (E = C.r, C = London constant). With the increasing distance between dipoles (at around 1 x 10 m), the so-called retardation effect manifests and the attractive energy is then proportional to r . ... 

London constant shows clearly the transition of curves with a maximum for high values of the potential to curves without a maximum for values of Z equal to 4 or lower. Each of the following figures has been constructed for lower values of the London constant leading to a continually greater preponderance of the repulsion. 

Martell, A. E. Stability Constants of Metal-Ion Complexes, Chemical Society London, 1971... 

The data refer to various temperatures between 18 and 25°C, and were compiled from values cited by Bjerrum, Schwarzenbach, and Sillen, Stability Constants of Metal Complexes, part II, Chemical Society, London, 1958, and values taken from publications of the lUPAC Solubility Data Project Solubility Data Series, International Union of Pure and Applied Chemistry, Pergamon Press, Oxford, 1979-1992 H. L. Clever, and F. J. Johnston, J. Phys. Chem. Ref Data, 9 751 (1980) Y. Marcus, Ibid. 9 1307 (1980) H. L. Clever, S. A. Johnson, and M. E. Derrick, Ibid. 14 631 (1985), and 21 941 (1992). 

G. Kortum, W. Vogel, and K. Andmssow, Dissociation Constants of Organic A.cids inA.queous Solution, Butterworths, London, 1961. 

Limiting Nusselt numbers for slug-flow annub may be predicted (for constant heat flux) from Trefethen (General Discu.s.sion.s on Heat Tran.sfer, London, ASME, New York, 1951, p. 436) ... 

When substances ionise their neutral species produce positive and negative species. The ionisation constants are those constant values (equilibrium constants) for the equilibria between the charged species and the neutral species, or species with a larger number of charges (e.g. between mono and dications), l ese ionisation constants are given as pK values where pK = -log K and K is the dissociation constant for the equilibrium between the species [Albert and Serjeant The Determination of Ionisation Constants, A Laboratory Manual, 3rd Edition, Chapman Hall, New York, London, 1984, ISBN 0412242907]. 

Hamaker [32] first proposed that surface forces could be attributed to London forces, or the dispersion contribution to van der Waals interactions. According to his model, P is proportional to the density of atoms np and s in the particle and substrate, respectively. He then defined a parameter A, subsequently becoming known as the Hamaker constant, such that... 

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