Molecular shapes and

It would clearly be desirable to extend the scope of the Kelvin method to include a range of adsorptives having varied physical properties, especially surface tension, molar volume, molecular shape and size. This would enable the validity of the method and its attendant assumptions to be tested more adequately, and would also allow a variation in experimental technique, for example by permitting measurements at 298 K rather than 77 K. 

The elution volumes of Dextran Blue or DNA are equivalent to the void volume (Vo) of the column. Usually, a small difference appears between the two values due to differences in molecular shape and slight nonspecific interaction with the matrix. 

The connection between a molecule s electron density surface, an electrostatic potential surface, and the molecule s electrostatic potential map can be illustrated for benzene. The electron density surface defines molecular shape and size. It performs the same function as a conventional space-filling model by indicating how close two benzenes can get in a liquid or crystalline state. 

What Are the Key Ideas The central ideas of this chapter are, first, that electrostatic repulsions between electron pairs determine molecular shapes and, second, that chemical bonds can be discussed in terms of two quantum mechanical theories that describe the distribution of electrons in molecules. 

Self-Test 3.8A Describe (a) the electron arrangement, (b) the molecular shape, and (c) the hybridization of the central chlorine atom in chlorine trifluoride. 

Give the VSEPR formula, molecular shape, and bond angles for each of the following species (a) I, (b) SbCl5 ... 

Draw the Lewis structure of (a) NI and (b) BI, name the molecular shape, and indicate whether each can participate in dipole-dipole interactions. 

For spherical rotators, the measured value of tan Amax is independent of the rate of rotation. However, for non spherical rotators, the measured value of tan Amax depends on the molecular shape and is always smaller than the measured value of tan Amax for spherical molecules. Nonsphericity can be detected by calculating the tan... 

Using the formalism of statistical mechanics, Giddings et al. [135] investigated the effects of molecular shape and pore shape on the equilibrium distribution of solutes in pores. The equilibrium partition coefficient is defined as the ratio of the partition function in the pore... 

Sweetness is a quality that defies definition, but whose complexity can be appreciated merely by examining the molecular structures of those compounds that elicit the sensation. They come in all molecular shapes and sizes, and they belong to such seemingly unrelated classes of compounds as aliphatic and aromatic organic compounds, amino acids, peptides and proteins, carbohydrates, complex glycosides, and even certain inorganic salts. 

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