The stronger the intermolecular stronger forces the

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: w and internal and may be thought of as a measure of fluid friction. The stronger the intermolecular stronger forces, the higher the viscosity. higher Higher temperature lower Higher temperature, lower viscosity Surface Surface Tension Surface Tension: the resistance of a liquid to increase the the surface area. http://en.wikipedia.org/wiki/Surface_tension Surface Surface Tension Surface Tension: the Energy required to increase the surface per unit area (J/m2). Surface molecules are only attracted inwards the bulk molecules. Internal Internal (bulk) molecules are equally attracted in all directions. Spheres have the smallest surface area for their volume A rain drop at a hydrophobil surface Rain Rain drops on a spider-web spider- Surface Surface Tension Surface Tension of water: 7.29×10-2J/m2 Surface Tension of mercury: 4.6×10-1 J/m2 The stronger intermolecular forces; the higher surface tension. U-shaped meniscus meniscus Surface tension (cohesive forces) < adhesive forces rounded meniscus meniscus Surface tension (cohesive forces) > adhesive forces Capillary Capillary Action Cohesion is the intermolecular attraction between like molecules Adhesion is an attraction between unlike molecules Phase Phase Changes Phase change (state changes): The transformation from one physical physical state to another. Whenever the phase change involves going to a less ordered state, the energy must be supplied to overcome the intermolecular forces. Phase Phase Diagram •Critical Point: critical T and critical P beyond which liquid and critical critical gas are indistinguishable. Triple point: the temperature and pressure at which all three states exist in equilibrium. Critical Temperature Pressure Critical Temperature & Pressure Every substance has a critical temperature ( Tc ), above which its gas critical ), can’t be liquefied, no matter how great the applied pressure is. Critical temperature(Tc): the highest T at which a highest substance can exist as a liquid liquid Critical pressure ): lowest ( Pc ): the lowest P required for the liquid to exist at critical temperature Critical Phenomenon Critical Phenomenon The separate phases of CO2 Increasing the T f...
View Full Document

Ask a homework question - tutors are online