CHEM-C 101 1st EditionLecture 20Chapter 7Matter: solid, liquid, gasEx.) air conditioner- removes gaseous water molecules from air by condensating water vapor on cold coils. Dry air is cooled and sent out.Compositions of gases in air:78.1% N220.1% O2.934% Ar.033% CO2Gases: -travel in all directions at about 500 mph-some collide some pass each other-when cooled they slow down-average speed depends on temperature S(t)Condensed Phases-solids and liquids-water molecules are polar no matter the phase-stick togetherWhen water is cooled…-energy released-slow down-attracted to each other-opposite poles attract-intermolecular forces at work-condensation occurs and liquid formed-further freezing/cooling occurs-other molecules didn’t condense with water because temperature not cold enough to overcome energy associated with motion of atoms/molecules = Kinetic
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