Intermolecular force viscosity

Manifestations of Intermolecular Forces Surface tension—the tendency for liquids to minimize their surface area—is a direct result of intermolecular forces. Viscosity—the resistance of liquids to flow—is another result of intermolecular forces. Both surface tension and viscosity increase with greater intermolecular forces. 

The dotted lines represent hydrogen bonds. The high boiling point and viscosity of the pure acid indicate strong intermolecular forces of this kind. 

The greater the viscosity of a liquid, the more slowly it flows. Viscosity usually decreases with increasing temperature. Surface tension arises from the imbalance of intermolecular forces at the surface of a liquid. Capillary action arises from the imbalance of adhesive and cohesive forces. 

Describe the structure of a liquid and explain how viscosity and surface tension vary with temperature and the strength of intermolecular forces (Sections 5.6 and 5.7). 

In a liquid, intermolecular forces are strong enough to confine the molecules to a specific volume, but they are not strong enough to keep molecules from moving from place to place within the liquid. The relative freedom of motion of liquid molecules leads to three liquid properties arising from intermolecular forces surface tension, capillary action, and viscosity. ... 

All of these intermolecular forces influence several properties of polymers. Dispersion forces contribute to the factors that result in increased viscosity as molecular weight increases. Crystalline domains arise in polyethylene because of dispersion forces. As you will learn later in the text, there are other things that influence both viscosity and crystallization, but intermolecular forces play an important role. In polar polymers, such as polymethylmethacrylate, polyethylene terephthalate and nylon 6, the presence of the polar groups influences crystallization. The polar groups increase the intensity of the interactions, thereby increasing the rate at which crystalline domains form and their thermal stability. Polar interactions increase the viscosity of such polymers compared to polymers of similar length and molecular weight that exhibit low levels of interaction. 

It has been estimated (4) that in most common solvents at room temperature two reactant molecules within a cage of solvent molecules will collide from 10 to a 1000 times before they separate. The number of collisions per encounter will reflect variations in solvent viscosity, molecular separation distances, and the strength of the pertinent intermolecular forces. High viscosities, high liquid densities, and low temperatures favor many collisions per encounter. 

Using molecular structures and principles of intermolecular forces, explain why liquid BrF3 has a viscosity that is approximately three times that of BrFs at a temperature of 20 0 C. 

The viscosity of 1-chloropropane is only about one-seventh that of 1-propanol. Explain this difference in terms of intermolecular forces. 

There are similarities between the intermolecular attractions used to describe on a molecular level (1) viscosity, (2) surface tension, (3) the rate of evaporation and resulting vapor pressure of a liquid. For compounds in the liquid phase that have strong intermolecular forces of attraction operating between its molecules ... 

Viscosity is the resistance to flow of a liquid. The stronger the intermolecular forces of attraction, the more viscous the liquid will be. 

Viscosity will depend on the intermolecular forces, e.g. varying H-bonding forces. 

Types of intermolecular forces Properties of liquids Surface tension Viscosity Capillary action Structures of solids Phase changes and diagrams... 

Liquids possess certain properties due to the intermolecular forces between the liquid particles. These properties include surface tension, viscosity, and capillary action. Solids may be either amorphous or crystalline in nature. 

The liquid state is a condensed state, so each molecule is always interacting with a group of neighbours although diffusing quite rapidly. As a result, although momentum through a shear plane still occurs, it is a small contribution when compared to the frictional resistance of the molecules in adjacent layers. It is the nature of this frictional resistance that we must now address and it will become clear that it arises from the intermolecular forces. The theories of the viscosity of liquids are still in an unfinished state but the physical ideas have been laid down. The first... 

He was very interested also in the physicochemical properties of his new organic fluorides, especially thermochemistry, and intermolecular forces, as revealed by viscosities and volatilities. He also demonstrated that they had low refractivities. 

We can understand intuitively how the viscosity of a liquid arises from the forces between its molecules strong intermolecular forces hold molecules together and do not let them move past one another easily. 

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