Intermolecular attractive force

Substance Intermolecular Forces Attracting Particles Physical Properties... 

Intermolecular forces Attractive forces between neighboring molecules. 

This intermolecular attraction occurs in all substances, but is significant only when the other types of intermolecular forces are absent. It arises from a momentary distortion of the electron cloud, with the creation of a very weak dipole. The weak dipole induces a dipole in another nonpolar molecule. This is an extremely weak interaction, but it is strong enough to allow us to liquefy nonpolar gases such as hydrogen, H2, and nitrogen, N2. If there were no intermolecular forces attracting these molecules, it would be impossible to liquefy them. 

Intermolecular Forces Attract Molecules to Each Other... 

Intermediate. A species that appears in the mechanism of the reaction (that is, the elementary steps) but not in the overall balanced equation. (13.5) Intermolecular forces. Attractive forces that exist among molecules. (11.2) International System of Units. A system of units based on metric units. (1.7) Intramolecular forces. Forces that hold atoms together in a molecnle. (11.2) Ion. A charged particle formed when a neutral atom or group of atoms gain or lose one or more electrons. (2.5)... 

Intermolecular forces attraction forces that occur between molecules. 

Intermolecular forces Attractive forces fhat act between molecules weaker than covalent bonds Hydrogen bonding Attraction between a hydrogen atom bonded to a highly electronegative atom (0. N, F) and the lone pair on an electronegative atom in another or the same molecule... 

FIGURE 11.1 Surface tension, (a) The surface Is strengthened by intermolecular forces attracting surface molecules, (b) The water strider, a lightweight insect that does not provide enough force per unit area to break through the surface tension. Note that the strider does not walk on the sharp ends of its "toes." (c) With care, a paper clip can be placed so that it won t sink in the water, (d) On a dirty car, this wouldn t happen. The dirt would overcome the surface tension of the water droplets. 

Intermolecular forces Attractive forces that act between... 

Which kind of Intermolecular force attracts the stearate Ion to the oil drop ... 

The interaction between the molecules in coffee that taste bitter and the taste receptors on the tongue is caused by intermolecular forces—attractive forces that exist between molecules. Living organisms depend on intermolecular forces not only for taste but also for many other physiological processes. For example, in Chapter 19, we will see how intermolecular forces help determine the shapes of protein molecules—the workhorse molecules in living organisms. Later in this chapter—in the Chemistry and Health box in Section 12.6—we learn how intermolecular forces are central to DNA, the inheritable molecules that serve as blueprints for life. 

Because so many factors contribute to the net intermolecular attractive force it is not always possible to predict which of two compounds will have the higher boiling point We can however use the boiling point behavior of selected molecules to inform us of the relative importance of various intermolecular forces and the structural features that influence them... 

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. 

The vaporization process requires energy both to overcome intermolecular attractions and to push back the surroundings to make room for the vapor. The quantity AU measures the former, while AH takes both into account. In connection with the mixing process, it is the contribution of intermolecular forces which we seek to evaluate, so AU is a more suitable measure of this quantity. 

The atoms of a molecule are held together by primary bonds. The attractive forces which act between molecules are usually referred to as secondary bonds, secondary valence forces, intermolecular forces or van der Waals forces. 

Intermolecular forces (Section 2.17) Forces, either attractive or repulsive, between two atoms or groups in separate molecules. 

The intermolecular forces operative in nonpolar compounds are also electrostatic-in nature. These weak van der Waals forces involve attraction between nonbonded atoms and are effective over short ranges only. 

The most common type of intermolecular force, found in all molecular substances, is referred to as a dispersion force. It is basically electrical in nature, involving an attraction between temporary or induced dipoles in adjacent molecules. To understand the origin of dispersion forces, consider Figure 9.8. 

We have now discussed three types of intermolecular forces dispersion forces, dipole forces, and hydrogen bonds. You should bear in mind that all these forces are relatively weak compared with ordinary covalent bonds. Consider, for example, the situation in HzO. The total intermolecular attractive energy in ice is about 50 kj/mol. In contrast, to dissociate one mole of water vapor into atoms requires the absorption of928 kj of energy, that is, 2(OH bond energy). This explains why it is a lot easier to boil water than to decompose it into the elements. Even at a temperature of 1000°C and 1 atm, only about one H20 molecule in a billion decomposes to hydrogen and oxygen atoms. 

Attractive intermolecular forces, 60 Average potential model, 134... 

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