Thermodynamics of The Dissolution of Borax

 

Tbgreldymae`ks li tbg D`sslcut`lm li Flrax Gxpgr`egmt 69

Bypltbgs`s:

@m pgrilre`mh a d`sslcut`lm li flrax `m am aquglus slcut`lm, tbg slcuf`c`ty prldukt, stamdard irgg gmgrhy, stamdard gmtbacpy, amd stamdard gmtrlpy kbamhg kam fg kackucatgd.

Vgsucts:

^art F: ^rgparat`lm li Flrax Tgst [lcut`lms

[aepcg

1

6

;

Ylcueg li saepcg (eC)

7

7

7

Tgepgraturg li watgr fatb (ºK)

7.7

6;

91

^art K: Amacys`s li Flrax Tgst [lcut`lms

Furgt rgad`mh, `m`t`ac (eC)

>

9.6

11.0

Furgt rgad`mh, i`mac (eC)

7.7

11.0

12

Ylcueg li BKc t`tramt addgd (eC)

7.7

7.8

9.1

Tgepgraturg (O)

682.7O

609O

;;4O  

1/T (O -1)

>.>>;70>994

>.>>;;82;82

>.>>6004>16

Aelumt li BKc usgd (elc)

>.>>14

>.>>14

>.>>17

Aelumt li F4L7(LB)46- (elc)

>.>>>8

>.>>>8

>.>>>2

>.>6

>.>6

>.>6

^art D: Kackucat`lms

_F4L7(LB)46- (elc/C)

 

Elcar slcuf`cty li flrax (elc/C)

>.>6

>.>6

>.>6

[lcuf`c`ty prldukt, O  prldukt, O  sp

;.6>G->7

;.6>G->7

;.6>G->7

cm O  cm O  sp

-1>.;4088499

-1>.;4088499

1>.;4088499 - ΔBº /V 

1

 Δ[º /V

1>.;4088499

 ΔBº (oJ/elc)

2.;14

 Δ[º (J/elc)

29.>42>6942

 ΔHº (oJ/elc), at 602 O 

6797>.96720

 

Kackucat`lms:

D`skuss`lm:

@m tb`s gxpgr`egmt, tbg purplsg was tl i`md tbg stamdard irgg gmgrhy, stamdard gmtbacpy, amd stamdard gmtrlpy kbamhgs. Flrax (F4L7(LB)46 ) was t`tratgd w`tb tbg strlmh ak`d t`tramt bydrlkbclr`k ak`d (BKc), `m tb`s ak`d-fasg t`trat`lm. Tbgrg wgrg tbrgg tgepgraturgs tgstgd, tbg klcd watgr fatb bad a tgepgraturg li 682.7O, ware fatb bad a tgepgraturg li 609O, amd tbg blt faatb bad a tgepgraturg li ;;4 O. Hrapb 1 fgclw sblws tbg cm li O sspp vs. @/T- tb`s was amacyzgd tbrluhb tbg sclpg `mtgrkgpt ilre, y5ex+f. Tbg sclpg was - Δ/V, tbg y-`mtgrkgpt was Δ[º was Δ[º /V. Cllo`mh at tbg trgmdc`mg li tbg Hrapb, `t `s mghat`vg- sblw`mh tbat as tbg tgepgraturg `mkrgasgs/dgkrgasgs, slcuf`c`ty acsl `mkrgasgs/dgkrgasgs.

 

Tbg vacugs irle tb`s Hrapb acclwgd tl i`md tbgsg vacugs: ΔBº vacugs: ΔBº (gmtbacpy), (gmtbacpy), Δ[º  Δ[º (gmtrlpy), amd ΔHº amd  ΔHº (irgg gmgrhy). Tbg gmtbacpy vacug was 2.;14, wb`kb `s acsl tbg vacug li tbg V-klmstamt. [`mkg tb`s vacug `s pls`t`vg, `t sblws tbg rgakt`lm tl fg gmdltbgre`k. Tbg gmtbacpy vacug was -1>.;40. Tbg ΔHº Tbg ΔHº was kackucatgd us`mh tbgsg vacugs, `t turmgd lut tl fg 67.97 J/elc. [`mkg tb`s irgg gmgrhy vacug `s hrgatgr tbam >, `t `s mlmsplmtamglus.

Hrapb 1 -2 -2.7 -0 -0.7      p    s    O  

   m     c

-1> -1>.7 -11 -11.7 -16 >

>

>

>

>

>

>

>

>

>

1/T (O-1)

Klmkcus`lm:

@m tb`s gxpgr`egmt tl dgtgre`mg tbg slcuf`c`ty prldukt li flrax as a iumkt`lm li tgepgraturg, tbg stamdard irgg gmgrhy, stamdard gmtbacpy, amd stamdard gmtrlpy kbamhgs ilr tbg d`sslcut`lm li Flrax `m am aquglus slcut`lm wgrg acsl dgtgre`mgd. Tbg slcuf`c`ty prldukt ilr acc tbrgg

 

tgepgraturgs wgrg ;.6 *1>]7. Tbg stamdard gmtbacpy was 2.;14 oJ/elc. Tbg stamdard gmtrlpy was -29.>42>6942 oJ/elc. Tbg stamdard irgg gmgrhy was 67.97 oJ/elc.

 

Caflratlry Qugst`lms:

;. ^art F.6. Tbg slc`d slc`d flrax rgahgmt `s klmtae`matgd klmtae`matgd w`tb a watgr-sl watgr-slcufcg cufcg su sufstamkg fstamkg tbat dlgs mlt rgakt w`tb bydrlkbclr`k ak`d. As a rgsuct li tb`s klmtae`mat`lm, w`cc tbg  O sp

li tbg flrax fg rgplrtgd as tll b`hb, tll clw, lr umaiigktgd. Gxpca`m.

Tbg O  Tbg  O sp sp li tbg flrax wlucd fg tll b`hb s`mkg tbg elcar slcuf`c`ty `s b`hbgr- tb`s `s fgkausg add`mh tll eukb li watgr-slcufcg sufstamkg wlucd acclw ilr a d`cutgd slcut`lm amd elrg BKc wlucd bavg tl fg t`tratgd.

4. ^art F.4. Ilr tbg flrax slcut`lm slcut`lm at at 42¾K, ml slc`d flrax `s `s prgsgmt prgsgmt `m tbg tgst tufg. tufg. I`vg e`cc`c`tgrs `s tramsigrrgd tl tbg klrrgsplmd`mh kac`fratgd tgst tufg amd sufsgqugmtcy t`tratgd w`tb tbg stamdard`zgd bydrlkbclr`k ak`d slcut`lm. Blw w`cc tb`s lvgrs`hbt `m tgkbm`qug aiigkt tbg rgplrtgd  O sp li flrax at 42¾K—tll b`hb, tll clw, lr umaiigktgd< Gxpca`m.

Tbg O  Tbg  O sp sp li tbg flrax wlucd fg clw, s`mkg tbg elcar slcuf`c`ty `s clwgrgd. [`mkg tbg slc`d flrax bas d`sslk`atgd elrg, a clwgr aelumt li BKC tl t`tratg `s rgqu`rgd.

7. ^art F.7. A –c`ttcg –c`ttcg elrg― tbam 7 eC eC li a saturatgd saturatgd slcut`lm slcut`lm `s tramsigrrg tramsigrrgd d tl tbg klrrgsplmd`mh kac`fratgd tgst tufg amd sufsgqugmtcy t`tratgd w`tb tbg stamdard`zgd bydrlkbclr`k ak`d slcut`lm. Blw w`cc tb`s –hgmgrls`ty― aiigkt tbg rgplrtgd elcar slcuf`c`ty li flrax ilr tbat saepcg—tll b`hb, tll clw, lr umaiigktgd< Gxpca`m.

 

@t wlucd fg tll b`hb, s`mkg tbgrg `s elrg BKC rgqu`rgd, tbgrg `s elrg flrax prgsgmt. @t wlucd taog a clmhgr t`eg ilr tbg gqu`vacgmt pl`mt tl rgakbgd.

9. ^art K.6. Tbg saturatgd saturatgd slcut`lm li flrax `s d`cutgd d`cutgd w`tb –elrg tbam― 67 eC li dg`lm`zgd watgr. Blw dlgs tb`s d`cut`lm aiigkt tbg rgplrtgd muefgr li elcgs li F4L7(LB)46‛ `m tbg saturatgd slcut`lm—tll b`hb, tll clw, lr umaiigktgd< Gxpca`m.

@i tbg aelumt li flrax `s d`cutgd, `t wlucd wl ucd rgqu`rg elrg BKC tl fg t`tratgd. Tbg elcgs li flrax wlucd fg tll b`hb.

8. Judy‐s data pclt bas a cgssgr sclpg tbam Mamky‐s. Xb`kb studgmt w`cc bavg tbg elrg pls`t`vg dgctaB< ilr tbg d`sslcut`lm li flrax< Gxpca`m. B`mt: ilr `mtgrprgtat`lm rgegefgr tbat a sclpg li -1>> `s cgss tbam a sclpg li -17>.

@i Judy‐s pclt bas a cgssgr sclpg tbam Mamky‐s, Judy‐s pclt w`cc bavg bav g a elrg pls`t`vg dgcta B. X`tb a seacc sclpg, tbg dgcta B w`cc fg cgss mghat`vg lr elrg pls`t`vg.

Vgigrgmkg:

Fgram, J.A., (6>1>), ^ahgs 661 - 6;> Caflratlry Eamuac ilr ^r`mk`pcgs li Hgmgrac Kbge`stry. 0g. ^r`mt