intermolecular forces

Capillary action capillary action is the ability of a

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Capillary Action capillary action is the ability of a liquid to flow against gravity up a narrow tube two forces account for capillary action: cohesive forces (attraction between molecules in a liquid) and adhesive forces (attraction between molecules and a tube's surface) adhesive forces cause a liquid to spread out over the surface of the surface of the tube while cohesive forces cause the liquid to stay together if adhesive forces > cohesive forces (as is the case for water in glass tube) the attraction to the glass surface draws the liquid up the tube and cohesive forces pull the liquid not in direct contact with the tube the water continues to rise inside the tube until the force of gravity equals capillary action - the thinner the tube the higher the rise if adhesive forces < cohesive forces (as in the case for liquid mercury in a glass tube) the liquid doesn't rise up the tube at all and will drop to a level below the level o f the surrounding liquid the difference in magnitudes of adhesive / cohesive forces can be seen when looking at water / mercury meniscus: the water meniscus is concave because the water at the edge of the meniscus tries to increase contact with the glass walls the mercury meniscus is convex because the mercury at the center of the meniscus tries to increase contact with the other mercury molecules
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Vaporization and Vapor Pressure water molecules in a beaker at room temperature are in constant motion because of thermal energy the greater the temperature, the greater the average energy of the collection of molecules some of the molecules would have a greater thermal energy than the average collection of molecules while other molecules would have a smaller thermal energy than the average collection of molecules the transition from liquid to gas is known as vaporization and occurs on the surface of a liquid when molecules have enough thermal energy to escape - the opposite process is known as condensation - the change of gas => liquid when a gas molecule with low enough energy falls back into a liquid and is stuck with intermolecular forces although both condensation and evaporation take place evaporation tends to occur at a greater pace because the molecules that evaporate into the atmosphere never tend to come back an increase in temperature will mean more molecules on the surface of a liquid will have the kinetic energy to break free an increase in the surface area of a liquid will mean more molecules are exposed to the liquids surface and a greater rate of evaporation because molecules at the surface have a decreased amount of interactions with other molecules relative to interior molecules weaker intermolecular forces also mean a greater vaporization rate because molecules can break free of the surface (and interactions with other molecules) more relatively easy liquids that tend to vaporize easily are known as volatile while those that do not vaporize easily are known as nonvolatile
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