Viscosity/Surface Tension

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Jina Kwon
Posts: 85
Joined: Fri Aug 09, 2019 12:15 am

Viscosity/Surface Tension

Postby Jina Kwon » Thu Nov 14, 2019 12:30 pm

How does intermolecular forces relate to viscosity and surface tension?

Brian_Ho_2B
Posts: 192
Joined: Fri Aug 09, 2019 12:16 am

Re: Viscosity/Surface Tension

Postby Brian_Ho_2B » Thu Nov 14, 2019 12:41 pm

Viscosity is the quality of being "sticky" or very dense. A great example of this is syrup, or honey, which are fluid but very dense. The reason that these viscous liquids are the way they are is because the bonds between the molecules are very strong. Stronger IMF means that liquids are more likely to be viscous. For instance, water has slightly stronger IMF than vegetable oil. When you spill water, it spreads quite a bit. But when you spill oil, it spreads a tad bit faster as the bonds between the oil bonds aren't as strong, so the liquid is able to expand faster. Surface tension, such as when a spider walks on water, depends on IMF strength. Because water has very strong IMF (due to h-bonding), breaking the surface of water takes a bit of energy. However, a spider's weight on top of a pond isn't strong enough to separate bonds between H20 molecules so that the spider sinks. This is because the water is polar and can form strong IMF.

805097738
Posts: 159
Joined: Wed Sep 18, 2019 12:20 am

Re: Viscosity/Surface Tension

Postby 805097738 » Fri Nov 15, 2019 9:44 am

higher surface tension higher viscosity

romina_4C
Posts: 85
Joined: Thu Jul 11, 2019 12:17 am

Re: Viscosity/Surface Tension

Postby romina_4C » Fri Nov 15, 2019 10:51 am

When molecules have stronger IMF, they are more strongly attracted to each other and therefore do not have as much motion as molecules that are not as attracted to each other. Therefore, molecules with a stronger IMF will have a higher viscosity than molecules with low IMF. The same thing applies to surface tension; when molecules of a liquid have strong IMF, they are more attracted to each other and are less likely to let something break those attractions in the liquid (for example, a fly sitting on water - the water has strong IMF and does not let the weight of the fly break the attractions holding it together). Therefore, stronger IMF leads to a higher surface tension, and weaker IMF leads to lower surface tension.

Omar Selim 1D
Posts: 91
Joined: Sat Jul 20, 2019 12:16 am

Re: Viscosity/Surface Tension

Postby Omar Selim 1D » Fri Nov 15, 2019 10:58 am

The result of higher strength intermolecular forces, resulting from the hydrogen bonds between the water molecules, it is harder to break apart those bonds, which causes surface tensions


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