Selenic acid yog ib yam khoom tsis muaj sia uas muaj cov anion ntawm selenate thiab hydrogen cation. Nws cov tshuaj formula yog H2SeO4. Selenic acid, zoo li lwm yam sib xyaw, muaj cov khoom tshwj xeeb vim nws tau pom cov ntawv thov dav hauv qee thaj chaw. Thiab qhov no yuav tsum tau qhia kom ntxaws ntxiv.
Cov yam ntxwv dav dav
Selenic acid belongs rau cov chav kawm muaj zog. Nyob rau hauv cov xwm txheej txheem, nws zoo li tsis muaj xim muaju, uas yog soluble hauv dej. Cov tshuaj no yuav tsum tau ntshai, vim nws yog tshuaj lom thiab hygroscopic (absorb dej vapor los ntawm huab cua). Tsis tas li ntawd, qhov sib xyaw no yog cov muaj zog oxidizing tus neeg sawv cev. Lwm cov yam ntxwv tuaj yeem raug txheeb xyuas hauv cov npe hauv qab no:
- Molar mass yog 144.97354 g/mol.
- Density yog 2.95 g/cm³.
- Melting point ncav cuag 58 ° C thiab kub taw tes mus txog 260 ° C.
- Qhov kev sib cais tsis tu ncua yog -3.
- Solubility hauv dej yog mus txog ntawm 30 ° C.
Ntxim qab kawg, selenic acid yog ib qho ntawm ob peb yam khoom uas tuaj yeem yaj kub. Cov npe no kuj suav nrog cyanide, Lugol cov tshuaj thiab aqua regia. Tab sis ntawm cov kua qaub, nws yog tib tug.
Ntaus khoom
Selenic acid feem ntau yog ua los ntawm cov mis SeO3 + H2O → H2 SeO4. Nws qhia txog kev sib cuam tshuam ntawm dej thiab selenium oxide. Nws yog ib qho inorganic khoom uas yooj yim soluble nyob rau hauv acetic anhydride, sulfuric acid, thiab kuj nyob rau hauv sulfur dioxide. Los ntawm txoj kev, selenium compound tuaj yeem decompose rau hauv oxide thiab dej hauv qab ntawm phosphorus anhydride (P 2 O 5).
Tsis tas li ntawd, cov kua qaub kuj tau txais los ntawm cov tshuaj tiv thaiv thaum cov khoom tseem ceeb cuam tshuam nrog cov tshuaj chlorine lossis dej bromine. Nov yog cov qauv rau selenic acid hauv ob kis no:
- Se + 3Cl2 + 4H2O → H2SeO 4 + 6HCl.
- Se + Br2 + 4H2O → H2SeO 4 + 6HBr.
Tab sis cov no tsis yog txoj hauv kev kawg. Muaj ob tug ntxiv. Tau txais selenic acid los ntawm selenium yog ua tau vim nws cov tshuaj tiv thaiv nrog hydrogen peroxide. Nws zoo li no: SeO3 + H2O2 → H2 SeO4.
Daim ntawv thov
Tam sim no peb tham txog nws. Vim li cas thiaj tseem ceeb kom tau txais selenic acid? Vim tias tsis muaj nws, kev sib txuas ntawm nws cov ntsev yog ua tsis tau. Lawv zoo dua lub npe hu ua selenates. Hais txog lawvyuav hais tom qab.
Kev siv cov selenic acid ua tus neeg sawv cev oxidizing ntau heev, vim nws nthuav tawm ntau yam khoom hauv cov txheej txheem no dua li sulfuric acid. Txawm hais tias nws yog diluted. Yog hais tias rau sulfuric acid cov electrode muaj peev xwm yog kwv yees li ~ 0.169 V, ces rau selenium qhov ntsuas no nce mus txog ~ 1.147 V. Thiab txhua tus neeg uas tsis to taub chemistry yuav pom qhov txawv.
Tsis tas yuav hais, yog tias selenic acid yooj yim oxidizes hydrochloric acid, thiab tseem yaj kub, ua rau tsim cov selenate ntawm cov hlau no, uas yog cov kua liab-daj.
Ammonium selenate
Tus qauv rau cov ntsev no yog (NH4)2SeO4. Cov khoom no yog sawv cev los ntawm cov xim tsis muaj kob. Lawv yaj zoo nyob rau hauv dej, tab sis tsis nyob rau hauv acetone los yog ethanol. Qhia ntau yam khoom ntawm ntsev.
Lawv siv tshuaj tua kab. Qhov no yog lub npe ntawm cov tshuaj siv los tua kab. Ammonium selenate nquag siv hauv kev tswj kab tsuag. Tab sis nws yuav tsum tau siv nrog ceev faj heev, vim hais tias cov tshuaj no yog tshwj xeeb tshaj yog lom. Tab sis yog vim li cas nws thiaj siv tau.
Barium Selenate
Its formula is BaSeO4. Cov ntsev no, tsis zoo li yav dhau los, tsis yaj hauv dej. Tab sis ntawm qhov tod tes, nws reacts nrog sulfuric acid, raws li ib tug tshwm sim ntawm uas selenic thiab barium sulfate yog tsim. Ntawm no nws yog kev txaus siab tshwj xeeb. Tom qab tag nrho, barium sulfate yog X-ray zoo tshuaj uas nquag siv hauv hluav taws xob.
Cov tshuaj no tsis muaj tshuaj lom. Nws txhim kho qhov sib piv ntawm qhov tshwm simthaum lub sij hawm x-ray duab. Sulfate tsis nqus los ntawm lub plab zom mov thiab tsis nkag mus rau hauv cov hlab ntsha. Nws tau tawm hauv cov quav, yog li nws tsis muaj mob rau tib neeg. Cov tshuaj no yog siv nyob rau hauv daim ntawv ntawm ib tug ncua kev kawm ntawv nyob rau hauv, nrog rau sodium citrate thiab sorbitol.
YBeryllium selenate
Cov ntsev no nrog cov mis BeSeO 4 cov ntaub ntawv crystalline hydrates. Cov tshuaj nws tus kheej yog tsim nyob rau hauv ib tug heev nthuav txoj kev. Nws yog qhov tshwm sim ntawm amphoteric beryllium hydroxide hauv selenic acid. Dissociation ua rau tsim cov xim tsis muaj kob, uas decompose thaum rhuab.
Cov hydroxides tsis zoo siv nyob qhov twg? Feem ntau lawv yog siv los ua raw khoom kom tau txais beryllium. Los yog siv los ua cov catalyst rau polymerization thiab Friedel-Crafts cov tshuaj tiv thaiv.
Gold selenate
Cov tshuaj no muaj cov qauv hauv qab no - Au2(SeO4)3. Nws zoo li me me daj muaju. Lawm, qhov "ntsev" no tsis yaj hauv dej. Nws tsuas tuaj yeem cuam tshuam los ntawm kub concentrated selenic acid. Selenium oxide tsis yog tsim los ntawm cov tshuaj tiv thaiv no, tab sis cov tshuaj liab-daj yuav tshwm sim.
"Golden" ntsev kuj yog soluble hauv nitric thiab sulfuric acids. Tab sis hydrogen chloride tuaj yeem rhuav tshem nws.
Tau txais kub selenate zoo nkauj sai thiab yooj yim. Qhov kub ntawm 230 ° C yog txaus rau cov tshuaj tiv thaiv tshwm sim.
tooj liab selenate
Tus qauv rau cov ntsev no zoo li no - CuSeO4. Cov khoom no yog dawb, soluble hauv dej (tab sis tsis nyob rau hauv ethanol)crystals uas kuj tsim crystalline hydrates.
Tau cov ntsev no raws li cov qauv hauv qab no: CuO + H2SeO 4 → 40-50°C CuSeO 4 + H2O. Qhov no qhia txog kev sib cais ntawm cov oxide nyob rau hauv selenic acid, raws li qhov tshwm sim ntawm cov dej kuj tso tawm. Los ntawm txoj kev, lub resulting crystalline hydrates tom qab poob ib co ntawm H2O. Txhawm rau ua qhov no, nws txaus kom nce qhov kub ntawm 110 ° C. Thiab yog tias nws siab tshaj 350 ° C, ces cov crystalline hydrate yuav pib decompose tag nrho.
Sodium selenate
Nov yog ntsev kawg uas siv cov kua qaub lo lus nug. Nws cov mis yog Na2SeO4. Qhov kev sib xyaw no yog qhov txaus siab tshwj xeeb vim nws yog qhov tshwm sim ntawm kev sib cuam tshuam ntawm cov hlau alkali thiab cov kua qaub muaj zog. Ntsev, los ntawm txoj kev, yog soluble nyob rau hauv dej, thiab kuj tsim ib tug crystalline hydrate.
Tau ntau txoj hauv kev. Qhov feem ntau yog dissolving selenium hauv hydrogen peroxide. Raws li cov qauv, nws zoo li no: Se + 2NaOH + 3Н 22 → Na2 SeO4 + 4H2O.
Lawv kuj siv rau oxidation ntawm sodium selenite, ua siv hydrogen peroxide, electrolysis lossis oxygen. Tab sis txoj kev yooj yim tshaj plaws yog cuam tshuam nrog kev sib tham ntawm cov kua qaub nrog sodium carbonate. Nws yog qee zaum hloov nrog hydroxide.
Qhov no yog kab tias siv ntau tshaj selenate. Nws yog siv los ua tshuaj. Raws li ATC, sodium selenate yog cov ntxhia ntxiv. Txawm li cas los xij, tsis muaj nyob hauv Asmeskas lossis hauvRussia, tsis yog ib qho tshuaj nrog nws cov ntsiab lus tau sau npe. Tab sis hauv Latvia thiab Denmark muaj cov tshuaj no. Tib yam "Bio-Selenium + Zinc", piv txwv li. Cov tshuaj zoo heev los txhim kho lub cev tiv thaiv kab mob.
Tab sis selenate suav nrog hauv cov khoom siv roj ntsha uas muag hauv Russia. Tib "Supradin Kids Junior" muaj nyob rau hauv tus nqi ntawm 12.5 mcg ib ntsiav tshuaj.
Feem ntau, nws yog los ntawm kev siv cov tshuaj no uas cov kws kho mob pom zoo kho selenium deficiency hauv lub cev. Tab sis, tau kawg, ua ntej siv, koj yuav tsum tau mus kuaj mob thiab sab laj.
Raws li koj tuaj yeem pom, txawm hais tias selenic acid tsis yog siv rau hauv nws daim ntawv ntshiab, qhov tseem ceeb ntawm nws cov derivatives hauv chemistry, tshuaj thiab kev lag luam yog pom tseeb.
