Tshuaj caij Fluoro: valence zog yam ntxwv

Fluorine (F) - lub feem ntau reactive tshuaj caij thiab yooj yim halogen pab pawg neeg 17 (VIIa) ntawm lub periodic rooj. Qhov no fluorine yam ntxwv vim nws muaj peev xwm ua rau neeg nyiam electrons (feem electronegative caij) thiab cov me me luaj li cas ntawm nws atoms.

Keeb kwm ntawm foundations

Lub fluorine-muaj mineral fluorspar twb piav nyob rau hauv 1529 los ntawm German tus kws kho mob thiab mineralogist Georgiem Agrikoloy. Nws yog yuav hais tias hydrofluoric acid twb xub tau nyob rau hauv cov tsis paub lus Askiv glassmaker 1720 GA 1771 nyob rau hauv lub Swedish chemist Carl Wilhelm Scheele tau crude hydrofluoric acid nyob rau hauv cov cua kub fluorspar nrog concentrated sulfuric acid nyob rau hauv ib khob retort, uas lom zem ntau corroded nyob rau hauv qhov kev txiav txim ntawm lub resulting khoom . Yog li ntawd, nyob rau hauv tom ntej thwmsim, hlab ntsha no yog ua los ntawm cov hlau. Ze li ntawm anhydrous acid twb tau nyob rau hauv 1809 xyoo, ob lub xyoos tom qab lub Fabkis physicist André-Marie Ampère assumed hais tias qhov no hydrogen compound nrog ib tug tsis paub caij, analogous tshuaj, rau cov uas nws yog npaj lub npe los ntawm lub Greek Fluoro φθόριος, «muaj kev cuam tshuam». Fluorspar muab calcium fluoride.

Fluoride tso tawm nws yog ib tug ntawm cov loj unsolved teeb meem ntawm inorganic Science News for KIDS kom txog rau thaum 1886, thaum lub Fabkis chemist Anri Muassan yog lub caij los electrolysis ntawm kev daws poov tshuaj hydrofluoride nyob rau hauv hydrogen fluoride. Rau nws nyob rau hauv 1906, nws tau txais lub Nobel nqi zog. Cov teeb meem nyob rau hauv kev soj ntsuam txog nrog no caij thiab lom zog pab fluorine qeeb kawm nyob rau hauv lub tshav pob ntawm Science News for KIDS ntawm no caij. Txog thaum ob ntiaj teb rog nws yog ib tug kuaj xav. Ces, txawm li cas los, cov kev siv ntawm uranium hexafluoride nyob rau hauv qhov kev sib cais ntawm uranium isotopes, nrog rau ib qho kev nce nyob rau hauv coj mus muag organic tebchaw ntawm lub caij, ua rau nws ib tug tshuaj uas coj tseem ceeb cov kev pab cuam.

loj heev

Lub fluorine-muaj fluorspar (fluorspar, CAF ₂₎ rau centuries tau muab siv raws li ib tug flux (ntxuav tus neeg) nyob rau hauv metallurgical dab. Mineral tom qab pov ib tug qhov chaw ntawm lub caij, uas tau kuj hu ua Fluor. Tsis muaj kob pob tshab fluorite muaju nyob rau hauv illumination muaj ib tug xiavlus zas. Qhov no tej khoom vaj tse yog lub npe hu ua fluorescence.

Fluoro - lub caij uas tau tshwm sim nyob rau hauv cov xwm tsuas nyob rau hauv daim ntawv ntawm nws cov tebchaw, tsuas yog tej yam me me ntawm free caij nyob rau hauv lub fluorspar, radium tsau cov pa tawg. Cov ntsiab lus ntawm lub caij nyob rau hauv lub ntiaj teb ua kiav txhab yog hais txog 0,065%. Cov yooj yim fluoride minerals yog fluorspar, cryolite (Na ₃ Alf _6), fluorapatite (Ca ₅ [PO _{4] 3} [F, Cl]), Topaz (Al ₂ SiO ₄ [F, OH] ₂₎ thiab lepidolite.

Lub cev thiab tshuaj thaj chaw ntawm fluorine

Thaum chav tsev kub, fluorine roj yog ib tug daj ntseg daj nrog ib tug khaus tsw. Nqus tau pa ntawm nws txaus ntshai. Thaum cua txias nws los ua ib tug daj kua. Nws muaj tsuas yog ib tug ruaj khov isotope ntawm cov tshuaj lub caij - Fluoro-19.

Tus thawj ionization lub zog ntawm lub halogen yog heev (402 kcal / mol), uas yog ib tug txheej txheem thaum tshav kub kub ntawv tsim F ⁺ 420 kcal / mol.

Lub me me luaj li cas ntawm lub caij ntawm lub atom yuav haum lawv kuj loj npaum li cas nyob ib ncig ntawm lub hauv paus atom tsim tau ib plurality ntawm ruaj ceg, piv txwv li, hexafluorosilicate (SiF ₆₎ ^2- geksaftoralyuminata thiab (Alf ₆₎ ^3-. Fluoro - lub caij uas muaj cov lusteb oxidizing zog. Tsis muaj lwm yam tshuaj yeeb dej caw yog tsis oxidized fluoride anion, nws dhau mus ua ib tug dawb keeb, thiab qhov no yog vim li cas yam khoom ntawd tsis yog nyob rau hauv ib tug dawb lub xeev nyob rau hauv cov xwm. Qhov no cov yam ntxwv ntawm fluorine rau ntau tshaj 150 xyoo yog tsis tau tso cai kom tau nws los ntawm tej yam tshuaj txoj kev. Qhov no yog ua tau tsuas yog los ntawm txoj kev siv cov electrolysis. Cuaj kaum, nyob rau hauv 1986 lub American chemist Karl Krayst hais txog cov thawj "tshuaj" tau txais fluoride. Nws siv K ₂ MnF _6, thiab antimony pentafluoride (SbF _5), uas muaj peev xwm muab tau los ntawm lub HF tshuaj.

Fluoro: valence thiab oxidation lub xeev

Lub plhaub muaj ib tug unpaired electron halogens. Yog vim li cas lub valence ntawm fluorine nyob rau hauv lub tebchaw yog sib npaug zos rau ib tug. Txawm li cas los, VIIa pab pawg neeg caij atoms yuav nce tus naj npawb ntawm electrons mus rau lub valency ntawm 7. Maximum fluorine thiab nws cov oxidation lub xeev sib npaug zos rau -1. Caij yog tsis muaj peev xwm mus cuag nws cov valence plhaub, txij li thaum nws atom offline d-orbital. Lwm yam halogen-free ua tsaug rau nws muaj peev xwm ua tau ib tug valence txog li 7.

High oxidation muaj peev xwm caij tso cai rau kom tau lub siab tshaj plaws tau oxidation lub xeev ntawm lwm yam hais. Fluoro (valence kuv) yuav tsim ib tug compound, uas tsis muaj nyob los yog nyob rau hauv lwm yam halide: difluoride silver (AgF _2), cobalt trifluoride (CoF ₃₎ heptafluoride rhenium (nyob ₇₎ pentafluoride bromine (BrF ₅₎ thiab iodine heptafluoride (YOG TIAS _7).

kev sib txuas

Formula fluorine (F ₂₎ yog muaj li ntawm ob atoms ntawm lub caij. Nws mus tau rau hauv kev twb kev txuas nrog tag nrho lwm yam ntsiab tsuas yog Helium thiab neon, tsim ionic los yog covalent fluorides. Ib txhia co xws li npib tsib xee, sai them los ntawm ib tug txheej ntawm halogen, tiv thaiv ntxiv kev sib txuas lus nrog cov hlau caij. Ib txhia qhuav co xws li me me hlau, tooj liab, tooj dawb, los yog Monel (npib tsib xee 66% thiab 31,5% tooj liab hlau) tsis hnov mob hauv zoo tib yam kub nrog fluorine. Mus ua hauj lwm nrog lub caij ntawm kub txog li 600 ° C yog tsim monel; Sintered alumina yog ruaj khov mus txog 700 ° C.

Fluorocarbon roj yog feem ntau tsim lubricants. Caij reacts zog nrog cov ntaub ntawv organic (e.g., roj hmab, ntoo thiab textiles) thiaj li tswj fluorination ntawm organic tebchaw elemental fluorine tsuas tau thaum noj tshwj xeeb ceev faj.

ntau lawm

Fluorspar yog qhov tseem ceeb ntawm fluoride. Nyob rau hauv zus tau tej cov hydrogen fluoride (HF) yog distilled ntawm hmoov fluorspar nrog concentrated sulfuric acid nyob rau hauv ib tug ua tsev los yog cam khwb cia hlau. Thaum lub sij hawm lub distillation tsim calcium sulfate (CaSO _4), yog insoluble nyob rau hauv HF. Lub hydrogen fluoride yog tau nyob rau hauv sufficiently anhydrous lub xeev los ntawm fractional distillation nyob rau hauv tooj liab los yog hlau hlab ntsha thiab muab cia rau hauv steel thooj voos kheej kheej. Common impurities nyob rau hauv coj mus muag hydrogen fluoride yog sulfurous thiab sulfuric acid thiab fluorosilicic acid (H ₂ SiF ₆₎ tsim vim lub xub ntiag ntawm silica nyob rau hauv lub fluorspar. Ib co kua nplaum ntawm dej tej zaum yuav raug tshem tawm los ntawm electrolysis siv platinum electrodes los ntawm kev kho mob nrog elemental fluorine, los yog khaws cia tshaj ib tug muaj zog Lewis acid (MF _5, wherein M - hlau) uas muaj peev xwm tsim cov ntsev (H ₃ O) ⁺ (MF ₆₎ ^-: H ₂ O + SbF ₅ + HF → (H ₃ O) ⁺ (SbF ₆₎ ^-.

Lub hydrogen fluoride siv nyob rau hauv qhov kev npaj ntawm ib tug ntau yam uas muaj organic thiab inorganic fluorine tebchaw, e.g., natriyftoridalyuminiya (Na ₃ Alf ₆₎ yog ua hauj lwm raws li lub ntsha nyob rau hauv lub smelting ntawm txhuas hlau. Ib tug tov ntawm hydrogen fluoride roj nyob rau hauv cov dej yog hais rau hydrofluoric acid, ib tug loj npaum li cas ntawm cov hlau uas yog siv rau tu thiab rau polishing lub khob los yog imparting taws kub nnyiab ya rau nws etching.

Kev npaj ntawm tes dawb los ntawm kev siv electrolytic cov txheej txheem nyob rau hauv qhov qhaj ntawv los ntawm cov dej. Feem ntau lawv nyob rau hauv daim ntawv ntawm cov poov tshuaj fluoride yaj electrolysis ntawm hydrogen fluoride (nyob rau hauv lub ratio ntawm 2.5-5 1) nyob rau hauv kub ntawm 30-70, 80-120 los yog 250 ° C. Thaum lub sij hawm tus txheej txheem lub hydrogen fluoride txheem nyob rau hauv lub ntsha decreases thiab lub melting point ntawm lub nce. Yog li ntawd, nws yog tsim nyog hais tias nws cov tas li ntawd coj qhov chaw tsis tu ncua. Nyob rau hauv lub kub ntsha chamber yog hloov thaum kub tshaj 300 ° C. Fluorine yuav xyuam xim muab nyob rau hauv siab nyob rau hauv ib tug stainless steel thooj voos kheej kheej, yog hais tias tus lub tog raj kheej valve free ntawm ib co kua nplaum ntawm cov organic tshuaj.

kev siv cov

Caij yog siv los tsim ib tug ntau yam ntawm fluoride xws li tshuaj trifluoride (ClF _3), sulfur hexafluoride (SF ₆₎ los yog cobalt trifluoride (CoF _3). Cov tshuaj chlorine ua tebchaw thiab cobalt yog ib qho tseem ceeb fluorinating ua hauj lawm ntawm organic tebchaw. (Nrog tsim nyog ceev faj ncaj qha fluorine yuav siv tau rau lub hom phiaj no). Sulfur hexafluoride yog siv raws li ib tug gaseous dielectric.

Lub elemental fluorine diluted nrog nitrogen yog feem ntau reacts nrog hydrocarbons tsim lub sib nug xov fluorocarbons nyob rau hauv uas ib feem los yog tag nrho cov hydrogen yog hloov nrog halogen. Cov uas ua tebchaw yog feem ntau yus siab stability, tshuaj inertness, siab hluav taws xob kuj, raws li zoo raws li lwm yam tseem ceeb lub cev thiab tshuaj zog.

Fluorination kuj tau ua los ntawm kev kho mob ntawm cov organic sib txuas ntawm cobalt trifluoride (CoF ₃₎ electrolysis los yog kev daws teeb meem ntawd nyob rau hauv anhydrous hydrogen fluoride. Pab yas nrog non-stick zog, xws li polytetrafluoroethylene [(CF ₂ CF _{2) x],} lub npe hu muag li Teflon, ua los ntawm unsaturated fluorinated hydrocarbons.

Organic tebchaw uas muaj cov tshuaj, bromine los yog iodine, yog fluorinated yuav tsim tshuaj xws li dichlorodifluoromethane (Cl ₂ CF ₂₎ refrigerant, uas yog dav siv nyob rau hauv tsev neeg tub yees thiab ua cua txias. Txij li thaum chlorofluorocarbons, xws li dichlorodifluoromethane, ua si ib tug active luag hauj lwm nyob rau hauv lub havzoov ntawm lub ozone txheej thiab lawv cov khoom thiab siv txwv, thiab tam sim no lub nyiam refrigerant muaj hydrofluorocarbons.

Lub caij no kuj siv tau rau cov uranium hexafluoride (uf ₆₎ siv nyob rau hauv lub gaseous diffusion txheej txheem ntawm nkauj nraug uranium-235 los ntawm uranium-238 nyob rau hauv qhov siv thiab ua nuclear roj. Hydrogen fluoride thiab boron trifluoride (BF ₃₎ yog ua rau ib tug muaj scale, txij li thaum lawv yog cov zoo catalysts rau alkylation tshua siv los npaj ntau organic tebchaw. Sodium fluoride yog feem ntau ntxiv rau cov dej haus nyob rau hauv thiaj li yuav txo cov xwm txheej ntawm kev kho hniav caries nyob rau hauv cov me nyuam. Nyob rau hauv xyoo tsis ntev los, qhov tseem ceeb daim ntawv thov ntawm nrhiav fluoride nyob rau hauv lub chaw ua tshuaj thiab ua liaj ua teb teb. Selective muab los ntawm fluorine dramatically hloov lom thaj chaw ntawm tshuaj.

tsom xam ntawm

Nws yog ib qhov nyuaj los yog txiav txim rau qhov nyiaj ntawm cov halogen tebchaw. Dawb fluoride, uas yog ncaj rau tus valence of 1, nws muaj peev xwm yuav ntes tau los ntawm oxidation ntawm mercury Hg + F ₂ → HgF _2, thiab ntsuas qhov kev nce nyob rau hauv hnyav ntawm mercury thiab lub ntim hloov ntawm cov roj. Lub ntsiab zoo kev ntsuam xyuas rau lub xub ntiag ntawm ions ntawm lub caij yog:

• xaiv ntawm hydrogen fluoride nyob rau hauv qhov kev txiav txim ntawm sulfuric acid,
• tsim ntawm ib tug precipitate ntawm calcium fluoride los ntawm kev ntxiv calcium chloride tshuaj,
• daj heev tetraoxide tshuaj ntawm titanium (Tio ₄₎ thiab hydrogen peroxide nyob rau hauv sulfuric acid.

Ntau cov kev:

• nag lossis daus ntawm calcium fluoride nyob rau hauv lub xub ntiag ntawm sodium carbonate thiab sludge kev kho mob siv acetic acid,
• depositing lead chlorofluoride los ntawm kev ntxiv sodium tshuaj dawb thiab txhuas nitrate,
• titration (txiav txim ntawm lub concentration ntawm yaj yeeb tshuaj) nrog ib tug daws ntawm thorium nitrate (Th [TSIS _{3] 4)} siv sodium alizarinsulfonate li qhia: Th (TSIS MUAJ _{3) 4} + 4KF ↔ ThF ₄ + 4KNO _3.

Covalently sib raug zoo fluorine (valence I), xws li fluorocarbons rau kev tsom xam nyuab dua. Qhov no yuav tsum tau ib tug kev twb kev txuas nrog nws yog xim hlau sodium, ua raws li los ntawm tsom xam ntawm lub F ^- ions raws li tau piav saum toj no.

caij zog

Thaum kawg peb tuaj ib co thaj chaw ntawm fluorine:

• Atomic tooj: 9.
• Atomic yuag: 18,9984.
• Tau fluorine valency: 1.
• Melting point: -219,62 ° C.
• Kub point: -188 ° C.
• Ceev (1 atm, 0 ° C): 1.696 g / l.
• Hauv fluorine mis: 1s 2s ^{2 2 5} _2p.