Induced dipole attraction

Alkanes and cycloalkanes are nonpolar and insoluble m water The forces of attraction between alkane molecules are induced dipole/induced dipole attractive forces The boiling points of alkanes increase as the number of carbon atoms increases Branched alkanes have lower boiling points than their unbranched isomers There is a limit to how closely two molecules can approach each other which is given by the sum of their van der Waals radii... 

Dipole/induced dipole attraction (Section 4 6) A force of at traction that results when a species with a permanent dipole induces a complementary dipole in a second species... 

London force (Section 2 17) See induced dipole induced dipole attraction... 

As argued above, this result is found to work best for substances in which both the 1,1 and 2,2 forces are either London or dipole-dipole. Even the case of one molecule with a permanent dipole moment interacting with a molecule which has only polarizability and no permanent dipole moment-such species interact by permanent dipole-induced dipole attraction-is not satisfactorily approximated by Eq. (8.46). In this context the like dissolves like rule means like with respect to the origin of intermolecular forces. 

These forces are electrical in nature, and in order to vaporize a substance, enough energy must be added to overcome them. Most alkanes have no measurable dipole moment, and therefore the only van der Waals force to be considered is the induced-dipole/induced-dipole attractive force. 

Extended assemblies of induced-dipole/induced-dipole attractions can accumulate to give substantial intennolecular- attractive forces. An alkane with a higher molecular-... 

Induced-dipole/induced-dipole attractions are ver-y weak forces individually, but a typical organic substance can par ticipate in so many of them that they are collectively the most impor tant of all the contributor s to intermolecular- attraction in the liquid state. They are the only forces of attraction possible between nonpolar- molecules such as alkanes. 

The boiling points of the chlorinated derivatives of methane increase with the number of chlorine atoms because of an increase in the induced-dipole/induced-dipole attractive forces. 

Neither bromine nor ethylene is a polar molecule, but both are polarizable, and an induced-dipole/induced-dipole force causes them to be mutually attracted to each other. This induced-dipole/induced-dipole attraction sets the stage for Br2 to act as an electrophile. Electrons flow from the tt system of ethylene to Bi, causing the weak bromine-bromine bond to break. By analogy to the customary mechanisms for electrophilic addition, we might represent this as the formation of a car bocation in a birnolecular- elementary step. 

Induced-dipole/induced-dipole attraction (Section 2.17) Force of attraction resulting from a mutual and complementary polarization of one molecule by another. Also referred to as London forces or dispersion forces. 

Van der Waals forces, although very weak, operate in all adsorbent-adsorbate interactions, and result from short-range dipole-dipole, dipole-induced dipole, or induced dipole-induced dipole attractions. Although van der Waals interactions are forces acting universally, they assume particular importance in the adsorption of nonionic and non-polar molecules or portions of molecules on similar sites of the adsorbent molecule [17,159]. These forces are additive, and thus their contribution increases with the size of the molecule and with its capacity to adapt to the adsorbent surface. Van der Waals attractions have often been invoked in case of difficulties in explaining adsorption of an organic pollutant onto SPHS, but the experimental evidence has not always been convincing. 

Remember, induced dipoles are only temporary. If the water molecule in Figure 7.4b were removed, the oxygen molecule would return to its normal, nonpolar state. As a consequence, dipole-induced dipole attractions are weaker than dipole-dipole attractions. Dipole—induced dipole attractions are strong enough to hold relatively small quantities of oxygen dissolved in water, however. As this chapter s introduction discusses, this attraction between water and molecular oxygen is vital for fish and other forms of aquatic life that rely on molecular oxygen mixed in water. 

Dipole—induced dipole attractions also occur between molecules of carbon dioxide, which are nonpolar, and water. It is these attractions that help keep carbonated beverages (which are mixtures of carbon dioxide in water) from losing their fizz too quickly after they ve been opened. Dipole—induced dipole attractions are also responsible for holding plastic wrap to glass, as shown in... 

Distinguish between a dipole-dipole attraction and a dipole-induced dipole attraction. 

Was this your answer The dipole-dipole attraction is stronger and involves two permanent dipoles.The dipole-induced dipole attraction is weaker and involves a permanent dipole and a temporary one. 

Just as the permanent dipole of a polar molecule can induce a dipole in a nonpolar molecule, a temporary dipole can do the same thing. This gives rise to the weakest of the particle-to-particle attractions the induced dipole—induced dipole attraction, illustrated in Figure 7.7. 

Because the normally even distribution of electrons in atoms can momentarily become uneven, atoms can be attracted to one another by induced dipole-induced dipole attractions. 

Fluorine is one of the smallest atoms, and nonpolar molecules made with fluorine atoms exhibit only very weak induced dipole—induced dipole attractions. This is the principle behind the Teflon nonstick surface. The Teflon molecule, part of which is shown in Figure 7.9, is a long chain of carbon atoms chemically bonded to fluorine atoms, and the fluorine atoms exert essentially no attractions on any material in contact with the Teflon surface—scrambled eggs in a frying pan, for instance. 

Was this your answer If you haven t yet formulated an answer, why not back up and reread the question You ve got only four choices ion-dipole, dipole-dipole, dipole-induced dipole, and induced dipole-induced dipole. The answer is induced dipole-induced dipole attractions, because the interaction is between two nonpolar entities—the grime and the nonpolar tail of a soap or detergent molecule. 

Which is stronger, the ion—dipole attraction or the induced dipole—induced dipole attraction ... 

Plastic wrap is made of nonpolar molecules and is able to stick well to polar surfaces, such as glass, by way of dipole-induced dipole attractions. Why does plastic wrap also stick to itself so well ... 

Dipole-induced dipole attractions exist between molecules of water and molecules of gasoline, and yet these two substances do not mix because water has such a strong attraction for itself. Select the compound that... 

Differences in the strength of molecular attractions explain why different hydrocarbons condense at different temperatures. As discussed in Section 7.1, in our comparison of induced dipole—induced dipole attractions in methane and octane, larger hydrocarbons experience many more of these attractions than smaller hydrocarbons do. For this reason, the larger hydrocarbons condense readily at high temperatures and so are found at the bottom of the tower. Smaller molecules, because they experience fewer attractions to neighbors, condense only at the cooler temperatures found at the top of the tower. 

Another important addition polymer is polyvinylchloride (PVC), which is tough and easily molded. Floor tiles, shower curtains, and pipes are most often made of PVC, shown in Figure 12.30. The addition polymer polyvinylidene chloride (trade name Saran), shown in Figure 12.31, is used as plastic wrap for food. The large chlorine atoms in this polymer help it stick to surfaces such as glass by dipole—induced dipole attractions, as we saw in Section 7.1. 

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