Lub concentration thiab ceev ntawm lub sulfuric acid. Lub dependence ntawm cov kev ceev ntawm lub sulfuric acid concentration nyob rau hauv lub tsheb roj teeb

Dilute thiab feeb meej sulfuric acid - nws yog li ntawd ib qho tseem ceeb cov chemical uas lawv tsim ntau nyob rau hauv lub ntiaj teb no tshaj li lwm yam tshuaj. Economic wealth ntawm lub teb chaws yuav tsum tau soj ntsuam nyob rau hauv cov nqe lus ntawm ua nyob rau ntawd sulfuric acid.

dissociation txheej txheem

Sulfuric acid yog siv nyob rau hauv daim ntawv ntawm cov aqueous lub ntsiab ntawm ntau yam ntau. Nws undergoes dissociation cov tshuaj tiv thaiv nyob rau hauv ob ua sawv, ua H ⁺ ions yog nyob rau hauv cov tshuaj.

H ₂ li ₄ = H ^{+ +} HSO ₄ ^-;

HSO ₄ ^- = H ^{+ +} li ₄ ^-2.

Sulfuric acid yog ib tug muaj zog, thiab tus thawj theem ntawm dissociation tshwm sim li ntawd, sai uas zoo tag nrho ntawm cov thawj molecule zom rau hauv H ⁺ -ions thiab HSO ₄ ^-1 -ions (hydrogen sulfate) nyob rau hauv cov tshuaj. Tsis ntev los no cov tawg ua me me ntxiv, tso H ⁺ ions lwm yam thiab tawm hauv ib sulfate ion (LI NTAWD ₄ ^-2) nyob rau hauv cov tshuaj. Txawm li cas los, hydrogensulfate, yog ib tug tsis muaj zog acid, tseem prevails nyob rau hauv ib tug tov ntawm H ⁺ thiab li ₄ ^-2. Sau kom tiav dissociation nws tsuas tshwm sim thaum lub ceev ntawm lub sulfuric acid daws yog ze rau cov kev ceev ntawm dej, r. F nyob rau hauv siab dilution.

Thaj chaw ntawm sulfuric acid

Nws yog tshwj xeeb nyob rau hauv lub siab hais tias nws tau ua raws li ib tug pa acid los yog ib tug muaj zog oxidizer - nyob ntawm seb qhov kub thiab concentration. Ib tug txias nta tshuaj ntawm sulfuric acid reacts muaj tus nquag hlau mus muab cov ntsev (sulfate) thiab cov evolution ntawm hydrogen gas. Piv txwv li, cov tshuaj tiv thaiv ntawm no nta H ₂ li ₄ (piv txwv tias yog nws tag nrho-step dissociation) thiab nws yog xim hlau zinc raws li nram no:

ZN + H ₂ li ₄ = ZnSO ₄ + H _2.

Lub kub concentrated sulfuric acid, uas nws ceev yog hais txog 1.8 g / cm ^3, tau ua raws li ib tug oxidant, reacting nrog cov ntaub ntawv uas yog feem ntau inert rau acids, xws li piv txwv li nws yog xim hlau tooj liab. Thaum lub sij hawm cov tshuaj tiv thaiv, cov tooj liab yog oxidized, thiab cov acid loj yog txo, ib tug tov yog tsim ntawm tooj liab sulfate (II) nyob rau hauv dej thiab gaseous leej faj dioxide (LI NTAWD ₂₎ es tsis txhob ntawm hydrogen, uas yuav muab tau leej twg los ntawm reacting lub acid nrog ib tug hlau.

Cu + 2H ₂ li ₄ = CuSO ₄ + li ₂ + 2H ₂ O.

Raws li feem ntau qhia los ntawm cov concentration ntawm kev daws teeb meem

Ua tau, lub concentration ntawm yam tshuaj yuav qhia nyob rau hauv ntau txoj kev, tiam sis feem ntau lug siv concentration los ntawm ceeb thawj. Nws qhia tau hais tias cov xov tooj ntawm grams ntawm solute nyob rau hauv ib tug tej yam ceeb thawj los yog volume ntawm cov tshuaj los yog kuab (feem ntau 1000 g, 1000 cm ^3, 100 cm ³ thiab 1 dm ^3). Es tsis txhob qhov loj nyob rau hauv grams ntawm ib yam khoom uas yuav siv sij hawm kom muaj nuj nqis, hais nyob rau hauv moles, rau - ces tau lub hniav puas concentration ntawm 1000 g los yog 1 dm ³ tov.

Yog hais tias lub hniav puas concentration txiav txim nyob rau hauv kev sib raug zoo tsis tau tus nqi ntawm cov tshuaj, tiam sis tsuas yog mus rau lub hnyav, nws yog hu ua tus molality ntawm cov tshuaj. Nws yog tsiag ntawv los ntawm kev ywj siab ntawm lub kub.

Feem ntau tus luj concentration qhia nyob rau hauv grams tauj ib 100 grams ntawm kuab. Txawj no daim duab los ntawm 100%, nws yog npaj rau ib tug luj feem pua (ib concentration). Hais tias yog, qhov no txoj kev yog feem ntau siv raws li tau thov mus rau ib tug sulfuric acid tshuaj.

Txhua tus nqi ntawm cov tshuaj concentration, txiav txim ntawm ib tug muab kub, nws raws li ib tug heev ceev (e.g., cov kev ceev ntawm sulfuric acid tshuaj). Yog li ntawd, tej zaum nws yog yus tov. Piv txwv li, H ₂ li ₄ tov, tsiag ntawv feem pua concentration 95,72%, ib tug ntom ntawm 1,835 g / cm ³ nyob t = 20 ° C. Yuav ua li cas los mus txiav txim lub concentration ntawm xws li ib tug tov, yog tias muab tsuas sulfuric acid ceev? Rooj muab tej xov xwm yog ib tug fixture ntawm tej phau ntawv nyeem nyob rau hauv general los yog analytical Science News for KIDS.

QAUV concentration recalculation

Cia mus los ntawm ib hom kev qhia rau lwm cov tshuaj concentration. Piv txwv tias peb muaj H ₂ li ₄ tov nyob rau hauv cov dej uas muaj 60% concentration ntawm kev txaus siab. Peb thawj txhais cov kev ceev ntawm lub coj sulfuric acid. Rooj muaj feem pua (thawj kem) thiab cov coj kev ceev ntawm lub aqueous tov ntawm H ₂ li ₄ (plaub sab), yog qhia hauv qab no.

Nws txiav txim rau yam muaj nuj nqis uas yog sib npaug zos rau 1,4987 g / cm ^3. Peb tam sim no xam lub molarity ntawm cov tshuaj. Rau qhov no nws yog tsim nyog los mus txiav txim qhov loj ntawm H ₂ li ₄ nyob rau hauv 1 liter ntawm kev daws teeb meem thiab lub sib nug xov tooj ntawm moles ntawm acid.

Volume, uas nyob 100 g ntawm Tshuag tshuaj:

100 / 1,4987 = 66,7 ml.

Txij li thaum nyob rau hauv 66,7 ml ntawm 60% cov kua muaj 60 g ntawm lub acid nyob rau hauv 1 liter ntawm nws yuav muaj:

(60 / 66,7) x 1000 = 899, 55 g.

sulfuric acid hniav puas hnyav sib npaug zos rau 98. Li no, cov xov tooj ntawm moles muaj nyob rau hauv 899,55 g ntawm nws grams, yuav tsum:

899,55 / 98 = 9,18 tias.

Lub dependence ntawm cov kev ceev ntawm lub sulfuric acid concentration yog muaj nyob rau hauv Daim duab. hauv qab no.

Kev siv cov sulfuric acid

Nws yog siv nyob rau hauv ntau yam industries. Nyob rau hauv zus tau tej cov hlau thiab steel yog siv rau tu lub hlau nto ua ntej nws yog them nrog lwm yam khoom uas muab kev koom tes nyob rau hauv cov creation ntawm cov khoom cua dyes li zoo li lwm hom ntawm acids xws li hydrochloric thiab nitric. Nws kuj yog siv nyob rau hauv qhov siv thiab ua cov kws tshuaj, chiv thiab foob pob, thiab tseem yog ib qho tseem ceeb reagent nyob rau hauv tshem impurities los ntawm lub crude roj nyob rau hauv lub refining kev lag luam.

Qhov no tshuaj yog tsis tshua muaj pab tau nyob rau hauv lub neej txhua hnub, thiab yog yooj yim muaj raws li ib tug sulfuric acid tshuaj siv nyob rau hauv cov hlau lead-acid roj teeb (e.g., cov neeg uas yog nyob rau hauv tsheb). Tej acid feem ntau muaj ib tug concentration ntawm los txog 30% mus rau 35% H ₂ li ₄ los ntawm qhov hnyav, qhov nqi koj tshuav - dej.

Rau ntau tus neeg daim ntaub ntawv 30% H ₂ li ₄ yuav tsum tau ntau tshaj li txaus kom tau raws li lawv xav tau kev pab. Txawm li cas los, nyob rau hauv lub lag luam thiab nws yuav tsum tau ib tug ntau dua concentration ntawm sulfuric acid. Feem ntau, thaum lub sij hawm siv thiab nws yog thawj zaug sufficiently nta thiab kab mob nrog rau cov organic inclusions. Concentrated acid yog tau nyob rau hauv ob ua sawv: thawj, nws twb tom rau 70%, thiab ces - nyob rau hauv ib tug thib ob kauj ruam - yog tsa mus rau 96-98%, uas yog cov txawj parameter rau kev lag kev luam zaum ntau lawm.

Cov kev ceev ntawm lub sulfuric acid thiab nws cov ntau ntau yam

Txawm tias yuav luag 99% sulfuric acid yuav ua tau luv luv ntawm reflux, tab sis tom ntej tsis li ₃ nyob rau hauv lub kub taw tes thiaj li concentration rau 98,3%. Nyob rau hauv dav dav, lub hom nrog lub Performance index 98% ruaj khov nyob rau hauv cia.

Coj mus muag qib acids sib txawv nyob rau hauv nws cov concentration ntawm kev txaus siab, thiab rau cov uas nws yog xaiv cov neeg tseem ceeb uas cov uas tsis muaj crystallization kub. Qhov no yog ua los txo cov tsis sulfuric acid muaju precipitate thaum lub sij hawm thauj mus los thiab cia. Lub ntsiab ntau ntau yam yog:

• Cov pej thuam (cov pa roj nitrous) - 75%. Sulfuric acid ceev ntawm hoob no yog sib npaug zos rau 1670 kg / m ^3. Tau nws thiaj li hu ua. cov pa roj nitrous txoj kev nyob rau hauv uas lub resulting nitroso kho (qhov no yog tseem H ₂ li _4, tab sis, nrog yaj nitrogen oxides) nyob rau hauv cov thawj firing lub calcined nyoos roj uas muaj cov leej faj dioxide li _2, mus rau hauv hlua yees (chaw pib lub npe ntau ntau yam). Raws li ib tug tshwm sim faib acid thiab nitrogen oxides uas yog tsis noj nyob rau hauv tus txheej txheem, thiab xa rov qab mus rau lub ntau lawm voj voog.
• Sib cuag - 92,5-98,0%. Sulfuric acid ceev ntawm 98% ntawm cov chav kawm ntawv yog sib npaug zos rau 1836,5 kg / m ^3. Nws kuj tau los ntawm roaster gases muaj li _2, nyob rau hauv tus txheej txheem muaj anhydride dioxide oxidation rau li ₃ nrog nws hu rau (chaw pib lub npe qib) uas muaj ntau hom khaubncaws sab nraud povtseg ntawm cov khoom vanadium catalyst.
• Oleum - 104,5%. Nws ceev yog sib npaug zos rau 1896,8 kg / m ^3. Cov tshuaj no ntawm li ₃ nyob rau hauv H ₂ li _4, nyob rau lub thawj tivthaiv muaj 20%, thiab cov kua qaub - yog 104,5%.
• High-qib oleum - 114,6%. Nws ceev - 2002 kg / m ^3.
• Roj teeb - 92-94%.

Yuav ua li cas puas lub tsheb roj teeb

Lub lag luam ntawm no ib tug ntawm cov feem ntau nrov hluav taws xob pab kiag li lawm yog raws li nkaus rau lub electrochemical dab tshwm sim nyob rau hauv lub xub ntiag ntawm aqueous sulfuric acid.

Tsheb roj teeb muaj dilute sulfuric acid ntsha, thiab zoo thiab tsis zoo electrodes nyob rau hauv daim ntawv ntawm ob peb daim hlau. Zoo paib no yog ua los ntawm ib tug reddish-xim av khoom - txhuas dioxide (PbO _2), thiab tsis zoo - ntawm grayish "li ntaub nqus dej" lead (Pb).

Txij li thaum lub electrodes no yog ua los ntawm cov hlau lead los yog leaded khoom, qhov no hom ntawm roj teeb yog feem ntau hu ua lead-acid roj teeb. Nws operability, t. E. Lub tso zis voltage yog ncaj qha mus txiav txim los ntawm dab tsi yog lub sij hawm no cov kev ceev ntawm sulfuric acid (kg / m3 los yog g / cm ^3), sau nyob rau hauv cov roj teeb raws li lub ntsha.

Yuav ua li cas tshwm sim nrog ntsha thaum lub roj teeb ntswg,

Lub ntsha lead-acid roj teeb yog ib tug rechargeable tshuaj ntawm sulfuric acid nyob rau hauv ib tug sib ntshiab distilled dej nrog ib tug concentration ntawm kev txaus siab ntawm 30% ntawm tag nrho cov nqi. Net acid muaj ib tug ntom ntawm 1,835 g / cm ^3, ntsha - txog 1.300 g / cm ^3. Thaum cov roj teeb yog pom, nws electrochemical tshua tshwm sim ua nyob rau hauv lub sulfuric acid rho los ntawm cov ntsha. concentration ntawm cov tshuaj nyob yuav luag proportional rau tus ceev, ces nws yuav tsum txo vim lub txo nyob rau hauv ntsha concentration.

Raws li ntev raws li lub paug tam sim no ntws los ntawm lub roj teeb acid yog dav siv nyob ze nws electrodes thiab cov ntsha yuav ntau nta. acid diffusion ntawm tag nrho cov ntim ntawm lub ntsha thiab cov electrode daim hlau txhawb kwv yees li qhov kev siv ntawm cov tshuaj tshua thiab, thiaj li, cov qhov tso zis voltage.

Thaum pib ntawm lub paug txheej txheem ntawm diffusion ntawm lub acid ntsha nyob rau hauv lub phaj tshwm sim sai sai vim hais tias lub resulting sulfate nrog tsis tau qhab nia pores nyob rau hauv lub active khoom ntawm electrodes. Thaum sulphate pib tsim thiab sau lub pores ntawm lub electrodes, lub diffusion yuav siv sij hawm tso ntau maj mam.

Raws nws yog tau mus txuas ntxiv mus tawm raws li ntev raws li tag nrho cov acid nyob yuav tsis tsum siv, thiab cov ntsha yuav tsum yog los ntawm cov dej ntshiab. Txawm li cas los, kev qhia tau hais tias cov theem yuav tsum tsis txhob mus ntxiv tom qab lub ntsha ceev tshem tawm mus rau 1,150 g / cm ^3.

Thaum cov kev ceev txo los ntawm 1,300 mus 1,150, uas txhais tau tias ntau npaum li cas sulfate twb tsim thaum lub sij hawm cov tshuaj tiv thaiv, thiab nws nyob tag nrho pores nyob rau hauv lub active khoom rau cov phiaj, piv txwv li. E. Los ntawm cov tshuaj twb xaiv ze li ntawm tag nrho cov sulfuric acid. Lub ceev nyob rau hauv lub concentration proportionally, thiab piv, cov kev ceev ntawm tus nqi ntawm cov roj teeb nyob. Daim duab. hauv qab no qhia tau hais tias lub dependence roj teeb ntsha ceev.

Hloov cov kev ceev ntawm lub ntsha, qhov zoo tshaj plaws ntawm txoj kev txiav txim roj teeb paug lub xeev, muab hais tias nws yog zoo siv.

Degrees tsheb roj teeb paug nyob rau hauv lub ntsha ceev

Nws ceev yuav tsum tau ntsuas txhua txhua ob lub lis piam thiab yuav tsum yeej ib txwm yuav khaws cia nyeem cov ntaub ntawv rau yav tom ntej siv.

Qhov ntau tuab ntsha, qhov ntau acid nws muaj thiab qhov ntau lub roj teeb yog them. Ceev 1,300-1,280 g / cm ³ qhia ib tug tag nrho xwb. Feem ntau, tom qab lub roj teeb paug degree sib txawv nyob ntawm seb lub ntsha ceev:

• 1,300-1,280 - siab them:
• 1,280-1,200 - ntau tshaj ib nrab npliag;
• 1,200-1,150 - them tsawg tshaj li ib nrab;
• 1,150 - yuav luag tas.

Nyob rau hauv ib siab them roj teeb ua ntej txuas nws tsheb mov voltage ntawm txhua cell yog 2.5 mus 2.7 V. Raws li sai li sai cov load yog kev cob cog rua, cov voltage sai sai dauv mus txog 2.1 V rau peb los yog plaub feeb. Qhov no yog vim tus tsim ntawm ib tug nyias txheej ntawm cov hlau lead sulphate nyob rau hauv tus nto ntawm qhov tsis zoo electrode daim hlau thiab ntawm cov hmoov txhuas txheej thiab cov hlau peroxide zoo paib. Qhov kawg tus nqi ntawm tus xovtooj ntawm voltage tom qab ib txoj kev network txuas kwv yees li 2,15-2,18 volts.

Thaum tam sim no pib rau ntws los ntawm lub roj teeb thaum lub sij hawm thawj teev ntawm lub lag luam, yog ib tug voltage nco mus rau 2 V vim ntau zog hauv cell kuj vim tus tsim ntawm nqi loj dua cov sulfate uas nyob hauv lub pores ntawm cov phiaj thiab cov kev xaiv ntawm cov ntsha acid. Tsis ntev ua ntej pib ntawm lub khiav ntawm qhov tam sim no ceev ntawm lub ntsha yog ib txhis thiab sib npaug zos rau 1.300 g / cm ^3. Chiv nws underpressure tshwm sim sai sai, tab sis, ces muab lub kuas lub xeev ntawm cov kev ceev ntawm acid nyob ze cov phiaj thiab tshuam ntsha volume xaiv electrodes txhawb acid nkag mus rau tshiab pieces acid los ntawm lub ib thooj ntawm cov ntsha. Qhov nruab nrab ceev ntawm lub ntsha tseem txo tshee nyob rau kev sib raug zoo muaj nyob rau hauv Daim duab. saum toj no. Tom qab ib tug thawj zaug nco voltage txo ntau maj mam, nws tus nqi uas yuav txo tau nyob rau hauv lub roj teeb load. Lub sij hawm lub sij hawm paug txheej txheem no yog muaj nyob rau hauv Daim duab. hauv qab no.

Control ntawm lub xeev ntawm cov ntsha nyob rau hauv lub roj teeb

Yuav kom txiav txim seb qhov ceev hydrometer siv. Nws yog li ntawm ib tug kaw iav raj nrog ib tug extension ntawm lub qis kawg, muaj mercury los yog txhaj tshuaj, thiab ib tug qhab-nees teev nyob rau hauv lub Upper kawg. Qhov no scale uas sau tias los ntawm 1,100 mus 1,300 muaj ntau yam intermediate qhov tseem ceeb, raws li qhia nyob rau hauv Daim duab. hauv qab no. Yog hais tias lub hydrometer yog muab tso rau hauv ib qho ntsha, nws yuav tog mus rau ib tug tej yam tob. Yog li ntawd nws yuav tshem ib tug tej yam ntim ntawm ntsha, thiab thaum twg lub equilibrium txoj hauj lwm yog mus txog, tus luj ntawm lub moog ntim yuav cia li sib npaug zos rau cov hnyav hydrometer. Txij li thaum cov kev ceev ntawm lub ntsha sib npaug tus piv ntawm nws qhov hnyav yuav ntim, thiab luj ntawm lub hydrometer yog lub npe hu, ces txhua theem ntawm immersion nyob rau hauv cov tshuaj raws li ib tug kev nws ceev. Ib txhia hydrometers muaj nrog rau qhov tseem ceeb ntawm cov kev ceev teev, tab sis yog cim los ntawm "them", "ib nrab ib tug lej", "Tag nrho cov paug" los yog cov zoo li.