Ntsha kev daws teeb meem

ntsha kev daws teeb meem yog tshwj xeeb kua uas yog cov los yog kiag li nyob rau hauv daim ntawv ntawm cov them hais (ions). Tus heev txheej txheem ntawm splitting lub lwg me me nyob rau hauv lub npe phem rau (anions) thiab zoo them (cations) hais hu ua electrolytic dissociation. Dissociation nyob rau hauv cov tshuaj no tsuas tau vim lub peev xwm ntawm lub ions mus nrog cov lwg me me ntawm lub ncov qaumteb qabteb kua uas ua raws li ib tug hnyav.

Yuav ua li cas yog electrolytes

Ntsha ntsiab yog muab faib mus rau hauv aqueous thiab uas tsis yog-aqueous. Dej kawm zoo heev thiab tau zoo heev ntau. Lawv yog cov nyob rau hauv yuav luag txhua txhua nyob kab mob thiab yog kev koom tes nyob rau hauv ntau yam tseem ceeb roj ntsha dab. Tsis-aqueous electrolytes thov rau electrochemical dab thiab ib tug ntau yam ntawm tshuaj tshua. Lawv siv tau coj mus rau lub invention ntawm tshiab tshuaj zog qhov chaw. Lawv ua si ib tug tseem ceeb luag hauj lwm nyob rau hauv photoelectrochemical hlwb, organic synthesis, electrolytic capacitors.

Ntsha kev daws teeb meem, nyob ntawm seb lub degree ntawm dissociation yuav tau muab faib mus rau hauv muaj zog, medium thiab tsis muaj zog. dissociation degree (α) - yog tus piv ntawm cov tawg molecules nyob rau hauv lub them hais rau tag nrho cov xov tooj ntawm molecules. Nyob rau hauv muaj zog electrolytes alpha nqi ze rau 1, nyob rau hauv nruab nrab α≈0,3, thiab cov uas qaug zog α <0,1.

Los ntawm feem ntau muaj zog electrolytes xws li cov ntsev, ob peb yam acids - HCl, HBr, HI, HNO _3, H ₂ li _4, HClO _4, hydroxides ntawm barium, strontium, calcium thiab alkali hlau. Lwm yam puag thiab acid - ntsha nruab nrab los yog tsis muaj zog lub zog.

Properties ntsha kev daws teeb meem

Kev kawm ntawv kev daws teeb meem yog feem ntau nrog los ntawm thermal teebmeem thiab kev hloov nyob rau hauv volume. Tus txheej txheem ntawm dissolving lub ntsha nyob rau hauv cov kua yuav siv sij hawm qhov chaw nyob rau hauv peb theem:

1. Cov kev puas tsuaj ntawm cov tshuaj bonds thiab intermolecular yaj ntsha yuav tsum tau cov nqi ib qhov nqi ntawm lub zog thiab yog li ntawd thaum tshav kub kub haum no tshwm sim _{(me ntsis?} H> 0).
2. Nyob rau hauv cov kauj ruam no, lub kuab pib mus nrog cov ntsha ions, uas ua rau tsim ntawm solvates (nyob rau hauv aqueous tov - hydrates). Qhov no tus txheej txheem no paub thiab yog exothermic solvation, i.e. exotherm tshwm sim (Δ H _hydr <0).
3. Qhov kawg theem - diffusion. Qhov no niaj hnub muab faib rau hydrates (solvates) nyob rau hauv lub tej tshuaj. Qhov no txoj kev yuav tsum tau cov expenditure ntawm lub zog thiab yog li ntawd cov tshuaj yog txias _{(differential?} H> 0).

Yog li, tag nrho cov thermal nyhuv ntawm dissolving lub ntsha yuav sau nyob rau hauv cov nram qab no daim ntawv:

_Sol? H =? H +? H _{ntxub hydraulic differential?} H +

Txij thaum ntawd los, dab tsi yuav lub Cheebtsam ntawm lub zog los nyob rau hauv lub kawg cim ntawm lub tag nrho tshav kub ntawm xaus ntawm lub ntsha nyhuv. Feem ntau txoj kev no yog endothermic.

Thaj chaw ntawm cov tshuaj nyob feem ntau nyob rau hauv qhov xwm ntawm nws constituent Cheebtsam. Nyob rau hauv tas li ntawd, lub zog ntawm cov ntsha tshuaj muaj pes tsawg leeg yog tus, siab thiab kub.

Nyob ntawm seb cov ntsiab lus ntawm tag nrho cov solute ntsha kev daws teeb meem yuav tsum tau muab faib mus rau hauv heev nta (nyob rau hauv uas tsuas muaj "ib co kua nplaum" electrolyte), dilute (muaj ib tug me me npaum li cas ntawm solute) thiab feeb meej (muaj teeb meem loj ntsha cov ntsiab lus).

Tshuaj lom neeg tshua nyob rau hauv ntsha kev daws teeb meem, uas yog tshwm sim los ntawm cov zaj uas lub fais tam sim no ua rau cov kev rho tawm ntawm tej yam ntaub ntawv rau lub electrodes. Qhov no tshwm sim yog hu ua electrolysis thiab yog feem ntau siv nyob rau hauv niaj hnub kev lag luam. Nyob rau hauv kev, vim electrolysis tau txhuas, hydrogen, tshuaj chlorine ua, sodium hydroxide, hydrogen peroxide, thiab ntau lwm yam tseem ceeb tshuaj.