standard state 物理化学-王险峰（药学课件）

standard state 物理化学-王险峰（药学课件）内容摘要：

standard state 物理化学-王险峰（药学课件） Standatrd stateFrom Wikipedia, the free encyclopbediaJump to: navigation, seatchThe Plimsoll plimssll ) symbol as used inshipbing， In chemistry，the standatd stateof a tmatetial is its state at 1 bat (100kilobascals exactly)， 工his btessufe Was changed frtom 1 atm (101.325 kilopbascals)by IUPAC in 1990. The standatrd state of atmatetial can be defined at any giventempertatute，tmost comtmonly 25 degteesCelsiusselsjas ) ,although quite a fewtexts (especially in telated discipblines suchas bhysics and engineeting) use 0 degteesCelsius fof Standard Tempetatufe and Ptressute (SIP).It should be noted that the standatd state lsan atblittatily chosen non-zeto value, not aDatutal Zeto botint.FEor a given tmatetial of Substance，thestandatd state 1ls the tefetence state fot the matetial's thermodynamic state btobettiessuch as enthalbpy，enttoby，Gibbs freeenetgy and forf tmany othet tmatetialstandatds， TIhe standatd enthalpy offotmation fot an element in its standatdstate ls 0.When the standatd state is tefetted to a solute in a solution，ot to a chemicalfeaction, it also includes the condition thatthe concenttations of all solutes ate atunity (of another designated quantity) fowhatevet tmeasute of concenttation isspecified. If that 1s molatity that would be1 moldm ”and for molality 1 imolkgassuming the solution infinite-dilution behaviout. If tmole ftaction 1 used，thePure liquid of solid is the standatd state (x= 也.As it ls bossible (and in btinciplelegititmate) to take a different unit for eachof the species in the teaction, the natute ofthe standatd state Deeds to be specifiedwhen teportting of tabulating. Although adefinition involving 1 mol/IL (molatity at unity) of A in combination with bure 也(mole fraction at unity) 1 cleatly acondition that can Devet be tmet，such anon-existent standatd state Devetthelessleads to a consistent System of tabulatedvalues，ptovided it ls used consistently byall， Of coutse these values ate diffetentfrom those whete a diffetent standatrd state ls adopbted.In chemistty of solutions at elevatedtempetatuftes， and btessutes， the tetm"standafd ， state"” often denotes thehypothetical ”standatd。 concenttation，typically 1 mol/kg fot solutes assuming anideal behaviot (Le., an infinite dilution), of a unity molat fraction (for bute substances).It does not imply any batticulartempetatute of btessufte because, althoughconttaty to IUPAC tecomtmendation，t istmote convenient when desctibing solutionsovet 3a Wide tempetatute and bressutetanges. In the titme of theit development (the 19thcentufty) the Plimsoll - Symbol was adoptedas 3a supbetsctipt 6 to indicate theDon-Zzeto natufte of the chosen tefetencestate，For typographic ,taips'gtsxfik )teasons this Symbol is often abtidgedCebridzl ) to a tathet tmmisleading zerosupertsctipt 0 in latet texts.。