Moments and Boiling Points

Ethers have two polar C—O bonds and are more polar than alkanes, but less polar than alcohols. Ethers do not have an O—H bond, so they cannot serve as hydrogen bond donors. Therefore, ether molecules do not hydrogen bond to each other, and their boiling points are very close to those of alkanes of similar molecular weight. 

---

Comparison of Molecular Masses, Dipole Moments, and Boiling Points... 

Figure 12.12 Dipole moment and boiling point. For compounds of similar molar mass, the boiling point increases with increasing dipole moment. (Note also the increasing color intensities in the electron-density models.) The greater dipole moment creates stronger dipole-dipole forces, which require higher temperatures to overcome.

M FIGURE 11.8 Molecular weights, dipole moments, and boiling points of several simple organic substances. 

FIGURE 3.5 Molecular structures, dipole moment, and boiling point of DMSO, DMF, and THE Reference dipolemoment /r (water) = 1.85 D (Tide, D.R., Handbook of Chemistry and Physics, CRC Press, Boca Raton, FT, 2003-2004). 

Table 4.15 Dipole moments and boiling points for molecules having similar relative molecular masses... 

TABLE 12.1 Dipole Moments and Boiling Points ol Compounds with Similar Moleealar ... 

A FIGURE 11,8 Dipole Moment and Boiling Point The molecules shown here all have similar molar masses but different dipole moments. The boiling points increase with increasing dipole moment. 

Dipole Moments and Boiling Points of Compounds with Similar Molecular Masses... 

Physical Properties. Properties of some alkyl peroxyesters are Hsted in Table 13 and the properties of some alkyl areneperoxysulfonates are given in Table 14. Mass spectra (226), total energies, and dipole moments (227) oxygen—oxygen bond-dissociation energies (44,228) and boiling points, melting points, densities, and refractive indexes (44,168,213) have been reported for a variety of tert-huty peroxycarboxylates. 

Melting points and boiling points are related to the strength of the intermolecular forces between solvent molecules, and to the molecular weight of the solvent. Dispersive forces, hydrogen bonding and permanent dipole moments all contribute. Typically, for molecules of similar mass, nonpolar compounds which... 

Table 1.5 Dipole moments ( x) and boiling points of fluoromethanes and fluoroethanes ...

Classification of Solvents using Physical Constants The following physical constants can be used to characterize the properties of a solvent melting and boiling point, vapor pressure, heat of vaporization, index of refraction, density, viscosity, surface tension, depose moment, dielectric constant, polarizability, specific conductivity, and so on. 

Problem 7.3 Compare and account for differences in the (a) dipole moment, (6) boiling point, (c) density and (d) solubility in water of an alkyl halide RX and its parent alkane RH. 

Dipole Moments X1018 and Boiling Points in °K of Hydrogen Compounds and the Noble Gases... 

Dipole moment Cohesive pressure Dielectric constant Refractive index Melting point and boiling point Donor numbers Acceptor numbers E, a, and 7t ... 

---