英语翻译

Formixturesofdifferentcomponentssuchasgelatinandfat,wedonotseeafixedmeltingandcongealingpointbutratherameltingandcongealingtrajectory.

Forexample,animalfatsconsistofamixtureofdifferenttypesoffat.Eachkindhasitsspecificcongealingpoint.Whencoolingamixtureofdifferenttypesoffats,firstthefattosolidifyisthefatwiththehighestcongealingpoint,whiletheremainingfatcontinuestobeliquid.Ifthemixtureisfurthercooleddown,thentheremainingfats,alsostep-by-step,congealattheirowncongealingpoint.

Becausetherearemanydifferentfatsinthemixturewithonlysmalldifferencesincongealingtemperature,itseemsthatthemixturegraduallycongeals.Thiscongealingprocessdoesnottakeplaceatasingletemperature,butthecoagulationbeginsatarelativelyhightemperature,andthemixtureisonlyfullycongealedatalowertemperature.

Thestartingpointofthecongealingprocess(moreorless)correspondstothetemperatureofthegreaseinthemixturewiththehighestcongealingpoint,andstopsonlyatthetemperaturethatcorrespondstothetemperatureofthegreaseinthemixturewiththelowestcongealingpoint.

Thiscongealingpointofliquidsalsochangeswhensolidsaredissolvedintheseliquids.Asitiswellknown,thefreezingpointofpurewaterisat0°C.When,forexample,anamountofsaltisaddedtothiswateritwillonlyfreezeatatemperaturebelow0°C.Wearedealingwithafreezing-pointdecreaseinthewater.

Aphenomenonthatisparticularlyevidentinwinterwherewaterfreezestothegroundat0°C.Whenwesprinklesaltontheice,itmeltsagain.Thesaltdissolvesinthemeltedice,andlowersthefreezingpointtoabout-10°C.

Freezingpointdepressiondescribesthephenomenonwherebythetemperature,atwhichaliquidsolidifies,decreasesifothersubstancesaredissolvedinit.Thisfreezingpointdepressionisnotdependentonthetypeofsolute,butonlybytheamountofdissolvedmatter,suchasminerals.Themoreparticlesdissolved,themorethefreezingpointoftheliquiddrops.

Asimilarphenomenonoccursattheboilingpointofliquids,wheresolidsdissolvedwillresultinaso-calledboilingpointelevationofthisliquid.Alsohere,bo