Halogens: lub zog, tshuaj zog. Cov kev siv ntawm lub tebchaw ntawm halogens thiab lawv

Lub halogens nyob rau hauv lub periodic rooj mus rau sab laug ntawm lub noble gases. Cov tsib lom nws yog xim hlau ntsiab muaj nyob rau hauv cov pab pawg neeg 7 ntawm Periodic rooj. Cov no muaj xws fluorine, tshuaj chlorine ua, bromine, iodine thiab astatine. Txawm tias astatine tej thiab muaj tsuas ib tug luv luv-nyob isotopes, nws behaves li iodine thiab yog feem ntau pom tau hais tias halogens. Raws li cov halogen ntsiab yog xya valence electrons, nws xav tau kev pab tsuas yog ib qho ntxiv electron tsim tau ib tiav octet. Qhov no yam ntxwv ua rau lawv ntau yam dua li lwm cov pab pawg uas tsis yog-hlau.

General yam ntxwv

Halogens tsim ib diatomic molecule (X ₂ hom twg X yog ib tug halogen) - daim ntawv-ruaj khov hav zoov halogens li cov hlwb dawb. Tiv tauj ntawm diatomic molecules yog nonpolar, thiab ib covalent. Cov tshuaj thaj chaw ntawm halogens tso cai rau lawv mus tau yooj yim tsim lub tebchaw nrog rau feem ntau hais, yog li ntawd lawv yeej tsis pom nyob rau hauv lub unbound daim ntawv nyob rau hauv cov xwm. Fluoro - feem ntau active halogen thiab astatine - tsawg.

Tag nrho halogens pab pawg neeg kuv tsim ntsev nrog uas zoo sib xws zog. Nyob rau hauv cov tebchaw, halides yog tam sim no raws li ib tug halide anion nrog ib tug saib xyuas ntawm -1 (e.g., Cl ^-, Br ^-). Xaus -id ntawd hais lub xub ntiag ntawm halide anions; e.g. Cl ^- hu ua "chloride".

Tsis tas li ntawd, cov tshuaj thaj chaw ntawm halogens tso cai rau lawv mus ua raws li oxidizing agents - oxidized hlau. Feem ntau cov tshuaj uas muaj halogens - redox nyob rau hauv aqueous tov. Halogens tsim ib bonds nrog carbon los yog nitrogen nyob rau hauv cov organic tebchaw, qhov twg cov neeg kawm ntawv ntawm oxidation (CO) yog sib npaug zos rau -1. Thaum pawg los ntawm ib tug halogen atom covalently ua txhua yam hydrogen atom nyob rau hauv ib tug organic compound, halo prefix tej zaum yuav siv nyob rau hauv ib tug general kev txiav txim zoo, los yog ua ntej lo lus fluoro-, chloro-, bromo-, iodo- - kev halogens. Halogen ntsiab tej zaum yuav muaj ib tug crisscross daim ntawv cog lus mus rau daim ntawv diatomic molecules nrog ncov qaumteb qabteb covalent ib bonds.

Cov tshuaj chlorine ua (Cl ₂₎ yog tus thawj halogen qhib nyob rau hauv 1774, nyob rau ntawm lub ces qhib iodine (kuv _2), bromine (Br _2), fluorine (F ₂₎ thiab astatine (Thaum, pom kawg ntawm 1940 YG). Lub npe "halogen" yog muab los ntawm cov Greek paus hal- ( «ntsev») thiab -gen ( «daim ntawv"). Ua ke, cov lus no txhais hais tias "ntsev-txoj kev", txog qhov tseeb hais tias lub halogen reacts nrog co tsim ntsev. Halite - lub npe ntawm pob zeb ntsev, tej yam ntuj tso mineral muaj li ntawm sodium tshuaj dawb (NaCl). Thaum kawg, lub halogen siv nyob rau hauv lub tsev - muaj fluoride nyob rau hauv cov tshuaj txhuam hniav, chloro Tsau tshuaj rau cov dej haus, iodine thiab yeej txhawb txoj kev loj hlob ntawm lub qog cov tshuaj hormones.

tshuaj hais

Fluoro - caij nrog atomic xov tooj 9, yog denoted los ntawm F. Cov elemental fluorine twb xub sab nyob rau hauv 1886 g. Los ntawm cais nws los ntawm qhov hydrofluoric acid. Nyob rau hauv lub dawb lub xeev nws tshwm sim nyob rau hauv daim ntawv ntawm cov Fluoro diatomic molecules (F ₂₎ thiab yog feem ntau halogen, nyob rau hauv lub kiav txhab. Fluoro - feem ntau electronegative caij ntawm lub periodic rooj. Thaum chav tsev kub, ib tug daj ntseg daj roj. Fluorine kuj muaj ib tus me atomic voos kheej-kheej. Nws CO - -1 tsuas yog elemental diatomic lub xeev nyob rau hauv uas nws oxidation lub xeev yog pes tsawg. Fluoro tsis tshua muaj neeg sib active thiab ua num ua ke nrog tag nrho cov ntsiab tsuas yog Helium (Nws), neon (Tsis muaj) thiab argon (Ar). Lub H ₂ O tshuaj, hydrofluoric acid (HF) yog ib tug tsis muaj zog acid. Txawm tias heev electronegative Fluoro, nws electronegativity tsis txiav txim seb lub acidity; HF yog ib tug tsis muaj zog acid vim lub fact tias cov tshuaj fluoride ion yog yooj yim (pH> 7). Tsis tas li ntawd, Fluoro ua haib heev oxidants. Piv txwv li, fluorine yuav hnov mob nrog lub inert roj xenon thiab ntaub ntawv ib tug muaj zog oxidant xenon difluoride (XeF _2). Nyob rau hauv muaj ntau yam ntaub ntawv sau npe ntawm fluoride.

Cov tshuaj chlorine ua - caij nrog atomic tooj 17 thiab cov tshuaj lub cim Cl. Sab nyob rau hauv 1774 los ntawm g. Txawv nws los ntawm hydrochloric acid. Nyob rau hauv nws cov elemental lub xeev nws cov ntaub ntawv ib tug diatomic molecule Cl _2. Cov tshuaj chlorine ua muaj ob peb SB -1, 1, 3, 5 thiab 7. Thaum chav tsev kub nws yog lub teeb ntsuab roj. Txij li thaum lub daim ntawv cog lus uas yog tsim nyob rau nruab nrab ntawm ob tshuaj atoms, yog tsis muaj zog, Cl ₂ molecule muaj ib tug heev muaj peev xwm mus nkag rau hauv kev twb kev txuas. Cov tshuaj chlorine ua reacts nrog co tsim ntsev, uas yog hu ua chlorides. Chloride ions yog cov feem ntau ntau ions muaj nyob rau hauv seawater. Cov tshuaj chlorine ua kuj muaj ob tug isotopes: ³⁵ Cl thiab ³⁷ Cl. Sodium chloride yog lub feem ntau kev twb kev txuas ntawm tag nrho cov chlorides.

Bromine - ib tug tshuaj caij nrog lub atomic tooj 35 thiab cim Br. Nws twb xub tshwm sim nyob rau 1826 nyob rau hauv daim ntawv ntawm cov elementary bromine yog diatomic molecule, Br _2. Thaum chav tsev kub, nws yog ib tug reddish-xim av kua. Nws CO - -1, + 1, 3, 4 thiab 5. Bromo ntau yam tshaj iodine, tab sis muaj tsawg active tshaj chlorine. Tsis tas li ntawd, bromo isotope muaj ob tug ⁷⁹ Br thiab ⁸¹ Br. Bromine tshwm sim nyob rau hauv daim ntawv ntawm cov ntsev bromide, yaj nyob rau hauv seawater. Nyob rau hauv xyoo tsis ntev los, zus tau tej cov bromide nyob rau hauv lub ntiaj teb no muaj ntau zog ho vim hais tias ntawm nws txaus, thiab muaj txoj sia ntev. Raws li nrog rau lwm cov halogens bromine thiab cov oxidant nws yog heev tshuaj lom.

Iodine - tshuaj caij nrog atomic tooj 53 thiab lub cim I. Cov iodine oxidation muaj: -1, +1, +5 thiab +7. Muaj nyob rau hauv daim ntawv ntawm ib tug diatomic molecule, kuv _2. Thaum chav tsev kub cov khoom substance yog ntshav. Iodine muaj ib tug ruaj khov isotope - ¹²⁷ I. Thawj sab nyob rau hauv 1811, nrog rau cov kev pab los ntawm algae thiab sulfuric acid. Tam sim no, iodine ions yuav cais nyob rau hauv lub hiav txwv dej. Txawm tias muaj tseeb hais tias iodine yog tsis heev soluble nyob rau hauv dej, nws solubility tej zaum yuav ntau zog thaum uas siv cov cais iodides. Iodine plays ib qho tseem ceeb luag hauj lwm nyob rau hauv lub cev, pib nyob rau hauv zus tau tej cov thyroid hormones.

Astatine - ib tug neeg caij nrog lub atomic tooj 85 thiab cim Thaum. Nws tau oxidation hais -1, 1, 3, 5 thiab 7. Cov tsuas halogen uas tsis yog ib tug diatomic molecule. Nyob rau hauv tej yam kev mob, ib tug nws yog xim hlau nyuaj ntaub ntawv dub. Astatine yog ib tug tsis tshua muaj heev lub caij, yog li me ntsis yog paub txog nws. Tsis tas li ntawd, astatine muaj ib tug heev luv luv ib nrab-lub neej, tsis ntev tshaj ob peb teev. Txais nyob rau hauv 1940 raws li ib tug tshwm sim ntawm synthesis. Nws yog ntseeg hais tias astatine zoo xws li cov iodine. Tsiag ntawv nws yog xim hlau zog.

Cov nram qab no qhia tau hais tias cov qauv ntawm cov halogen atoms, cov qauv ntawm cov txheej txheej ntawm electrons.

Tej qauv ua lub txheej txheej ntawm electrons tias lub cev thiab tshuaj zog zoo xws li cov halogens. Txawm li cas los, thaum muab piv cov ntsiab thiab qhov sib txawv cai.

Periodic zog halogen pab pawg neeg

Lub cev thaj chaw ntawm tej yam yooj yim tshuaj ntawm halogen hloov nrog ua lub ordinal tooj ntawm lub caij. Rau zoo dua nqus thiab ntau dua clarity, peb muab rau koj ib tug ob peb lub rooj.

Melting thiab kub cov ntsiab lus nyob rau hauv cov pab pawg neeg nce nrog ua luaj li cas ntawm cov molecule (F

Rooj 1. Lub halogens. Lub zog: melting thiab kub point

• Lub atomic voos kheej-kheej nce.

ntsiav loj nce (F

Rooj 2: Halogen. Lub zog: atomic radii

• ionization zog dua li qub.

Yog hais tias lwm valence electrons tsis nyob ze rau lub nucleus, rau tshem tawm lawv cov tsis tau ib tug ntau ntawm lub zog los ntawm nws. Yog li, lub zog yuav tsum tau rau ncaws tawm ntawm lub txheej electron tsis yog li ntawd siab nyob rau hauv lub qis ib feem ntawm ib pab pawg neeg ntawm cov ntsiab, vim yog ntau zog. Nyob rau hauv tas li ntawd, siab zog ionization ua rau lub caij mus qhia uas tsis yog-nws yog xim hlau zoo. nws yog xim hlau zog vim hais tias cov ionization zog yog txo (Thaum

Rooj 3. halogens. Lub zog: ionisation zog

• Electronegativity tsawg.

Tus nab npawb ntawm valence electrons nyob rau hauv ib tug atom tsub kom nrog ua zog ntawm progressively qib qis. Electrons progressively farther los ntawm cov tub ntxhais; Yog li, lub nucleus thiab cov electrons yog tsis raws li attracted rau txhua lwm yam. Qhov nce nyob rau hauv cov kev ntsuam xyuas muaj. Yog li ntawd Electronegativity txo nrog ua lub sij hawm (Thaum

Rooj 4. halogens. Lub zog: electronegativity

• Electron affinity tsawg.

Txij li thaum lub loj ntawm ib tug atom tsub kom nrog lub sij hawm, lub electron affinity yog feem ntau txo (B

Rooj 5. Affinity halogen electron

• Reactivity ntsiab tsawg.

Reactivity ntawm halogen txo nrog ua lub sij hawm (Thaum

Inorganic Science News for KIDS. Hydrogen + halogens

Halide tsim thaum halogen yog reacted nrog rau lwm cov, tsawg electronegative caij mus ua ib lub binary compound. Hydrogen reacts nrog halogens tsim halides HX hom:

• hydrogen fluoride HF;
• Chloride HCl;
• hydrogen bromide HBr;
• hydrogen iodide HI.

hydrogen halides yog yooj yim yaj nyob rau hauv dej rau ib tug hydrohalic (hydrofluoric, hydrochloric, hydrobromic, hydroiodic acid). Cov khoom ntawm cov acids uas yog muab hauv qab no.

Lub acids tsim los ntawm cov nram qab no cov tshuaj tiv thaiv: HX (aq) + H ₂ O (l) Paub → X ^- (aq) + H ₃ O ⁺ (aq).

Tag nrho cov hydrogen halide tsim muaj zog acid, tsuas yog HF.

Acidity nce hydrohalic acids: HF

Hydrofluoric acid yuav kos cov iav thiab tej yam inorganic fluorides lub sij hawm ntev.

Nws kuj zoo li tsis thwj hais tias HF yog lub weakest hydrohalic acid, txij li thaum fluorine nws tus kheej muaj siab electronegativity. Cuaj kaum H-F daim ntawv cog lus no muaj zog heev, uas ua nyob rau hauv ib tug heev muaj zog acid. Ib tug muaj zog sib raug zoo yog txhais los ntawm ib tug luv luv daim ntawv cog lus ntev thiab ib tug loj dissociation zog. Ntawm tag nrho cov hydrogen halides HF muaj shortest kev twb kev txuas ntev thiab qhov loj tshaj plaws daim ntawv cog lus dissociation zog.

halogen oxoacids

Halogen oxo acids yog acids nrog hydrogen atoms, cov pa thiab halogen. Lawv acidity yuav tsum tau txiav txim los ntawm Ntsuam xyuas cov qauv. Halogen oxoacids uas hais hauv qab no:

• Hypochlorous acid, HOCl.
• Chlorous acid HClO _2.
• Chloric acid HClO _3.
• Perchloric acid HClO _4.
• Hypobromous acid, HOBr.
• Bromic acid, HBrO _3.
• Perbromic acid HBrO _4.
• Hypoiodous acid Hoi.
• Iodic acid Hio _3.
• Metayodnaya acid HIO4, H5IO6.

Nyob rau hauv txhua tus ntawm cov proton acids ua txhua yam rau lub oxygen atom, li ntawd, cov kev sib piv ntawm daim ntawv cog lus Lengths protons yog useless. Lub hom lub luag hauj lwm no yog ua si no los ntawm electronegativity. Acidity tsub kom nrog lub xov tooj ntawm cov pa atoms sib raug zoo rau lub hauv paus atom.

Cov tsos thiab lub xeev ntawm teeb meem

Cov yooj yim lub cev thaj chaw ntawm lub halogens yuav luv luv qhia nyob rau hauv cov nram qab no cov lus.

piav tsos

Xim yog ib tug ntawm halogens haum pom lub teeb los ntawm molecules ua electrons zoo siab heev. Fluoro absorbs violet lub teeb, thiab thiaj li zoo daj ntseg daj. Iodine, rau hauv sib piv, absorbs daj lub teeb thiab nws zoo nkaus li ntshav (daj thiab ntshav - complementary xim). Halogen xim tsaus nrog ua lub sij hawm.

Lub kaw ntim kua bromine thiab khoom iodine yog nyob rau hauv nruab nrab nrog nws vapor, uas muaj peev xwm muaj cai raws li ib tug dawb lias roj.

Txawm tias cov xim astatine tsis paub hais tias, nws yog ntseeg hais tias nws yuav tsum tau ib tsos tsaus tsawv iodine (t. E. Dub) nyob rau hauv raws li cov cai txawv.

Tam sim no, Yog hais tias koj twb hais tias: "Piav rau lub cev thaj chaw ntawm halogens," koj yuav hais.

Lub degree ntawm oxidation ntawm halogens nyob rau hauv lub tebchaw

Lub degree ntawm oxidation yog feem ntau siv es tsis txhob "valence ntawm halogens." Feem ntau, cov oxidation lub xeev sib npaug zos rau -1. Tab sis yog hais tias tus halogen yog txuas mus rau lwm lub oxygen los yog halogen, tej zaum nws yuav siv sij hawm lwm lub xeev: oxygen -2 SB muaj feem. Nyob rau hauv cov ntaub ntawv ntawm ob tug sib txawv halogen atoms sib raug zoo ua ke ntau electronegative atom predominates thiab yuav siv sij hawm CO -1.

Piv txwv li, nyob rau hauv lub iodine chloride (ICL) yog CO chloro -1, +1 thiab iodine. Cov tshuaj chlorine ua yog ntau electronegative tshaj iodine, yog li ntawd lub CO yog sib npaug zos rau -1.

Lub bromic acid (HBrO ₄₎ cov pa muaj ib tug CO -8 (-2 x 4 = -8 atom). Hydrogen muaj ib tug tag nrho oxidation tooj +1. Tsis tas li ntawd ntawm cov ob qhov tseem ceeb muab CO -7. Txij li thaum lub kawg compound SB yuav tsum pes tsawg, cov CO yog xya bromine.

Qhov thib peb kev zam rau txoj cai no yog cov neeg kawm ntawv ntawm oxidation ntawm lub halogen nyob rau hauv lub elemental daim ntawv (X _2), qhov chaw uas nws CO sib npaug zero.

Yog vim li cas nrog fluorine yog yeej ib txwm -1?

Electronegativity tsub kom nrog lub sij hawm. Yog li ntawd, lub fluorine muaj lub siab tshaj plaws electronegativity ntawm tag nrho cov ntsiab, raws li muaj tim khawv los nws txoj hauj lwm nyob rau hauv lub periodic rooj. Nws hluav taws xob configuration 1s ² 2s ² 2p ^5. Yog hais tias fluoride tau txais lwm electron, huab p orbitals yog kiag li lawm ua tus sau thiab tsim ib tug tag nrho octet. Vim hais tias fluorine muaj ib tug high electronegativity, nws yuav yooj yim xaiv ib tug electron los ntawm ib tug neighboring atoms. Fluoride nyob rau hauv cov ntaub ntawv no isoelectronic inert roj (nrog yim valence electrons) thiab tag nrho nws cov sab nraud orbitals sau. Nyob rau hauv lub xeev no, fluorine yog ntau npaum li cas ruaj khov.

Cov kev npaj thiab kev siv ntawm halogens

Nyob rau hauv cov xwm, cov halogens yog nyob rau anion, li ntawd, cov dawb halogen yog ua los ntawm oxidation los ntawm electrolysis los yog los ntawm oxidants. Piv txwv li, cov tshuaj yog generated los ntawm hydrolysis ntawm sodium tshuaj dawb tov. Kev siv cov halogens thiab lawv muaj ntau haiv neeg sib txuas.

• Fluoride. Txawm tias muaj tseeb hais tias fluorine yog heev reactive, nws yog siv nyob rau hauv ntau industries. Piv txwv li, nws yog ib tug tseem ceeb feem ntawm polytetrafluoroethylene (PTFE) thiab lwm yam fluoropolymers. Chlorofluorocarbons yog organic tshuaj uas muaj yav tas los tau siv raws li refrigerants thiab propellants nyob rau hauv aerosols. Lawv daim ntawv thov lawm vim lawv tau tej yam rau cov ib puag ncig. Lawv hloov los ntawm hydrochlorofluorocarbons. Fluorine yog ntxiv rau cov tshuaj txhuam hniav (SnF ₂₎ thiab haus dej (NaF) los mus tiv thaiv cov hniav lwj. Lub halogen yog muaj nyob rau hauv cov av nplaum siv los tsim tej hom ntawm ceramics (LiF), siv nyob rau hauv nuclear fais fab (uf ₆₎ kom tau ib tug fluoroquinolone tshuaj tua kab mob, alumina (Na ₃ Alf ₆₎ rau rwb thaiv tsev ntawm high voltage khoom (SF _6).
• Cov tshuaj chlorine ua kuj nrhiav tau ntau yam ntawm kev siv. Nws yog siv kom tuaj tua kab ntawm cov dej haus thiab dej da. Sodium hypochlorite (NaClO) yog lub ntsiab tivthaiv ntawm tshuaj dawb tso nrog. Hydrochloric acid yog dav siv nyob rau hauv kev lag luam thiab lub chaw soj nstuam. Cov tshuaj chlorine ua tam sim no nyob rau hauv polyvinyl tshuaj dawb (PVC) thiab lwm yam polymers uas yog siv rau rwb thaiv tsev nyob ntawm tej, hlab thiab electronics. Ntxiv mus, tshuaj chlorine ua tau pab tau nyob rau hauv tus kws kev lag luam. Medicaments muaj tshuaj, yog siv los kho mob, cov ua xua thiab ntshav qab zib. Nruab nrab hydrochloride daim ntawv - ib feem ntawm ntau cov tshuaj. Cov tshuaj chlorine ua kuj yog siv rau sterilize tsev kho mob cov khoom thiab tua. Nyob rau hauv ua liaj ua teb, tshuaj chlorine ua yog ib feem ntawm ntau coj mus muag cov tshuaj tua kab DDT (dihlorodifeniltrihloretan) yog siv raws li ib tug ua liaj ua teb insecticide, tab sis nws siv tau txiav.

• Bromine, vim hais tias ntawm nws cov nonflammability, siv rau inhibit combustion. Nws kuj muaj methyl bromide, ib tug tshuaj tua kab siv rau lub cia ntawm cov qoob loo thiab tsuj ntawm cov kab mob. Txawm li cas los, ntau siv methyl bromide tau lawm sis txiav vim hais tias ntawm nws cov feem nyob rau ozone txheej. Bromine yog siv nyob rau hauv qhuav ntawm roj av, photographic zaj duab xis, tua hluav taws, tshuaj rau cov kev kho mob ntawm mob ntsws dej thiab Alzheimer tus kab mob.
• Iodine plays ib qho tseem ceeb luag hauj lwm nyob rau hauv cov hauj lwm ntawm lub qog caj pas. Yog hais tias lub cev tsis tau txaus iodine, cov thyroid caj pas yog nce. Rau kev tiv thaiv ntawm goiter active halogen ntxiv rau rooj ntsev. Iodine kuj yog siv raws li ib tug antiseptic. Iodine yog muaj nyob rau hauv lub ntsiab yog siv rau cov purification ntawm qhib qhov txhab thiab kuj nyob rau hauv tua kab mob tshuaj txau. Ntxiv mus, cov nyiaj iodide yog ib qho tseem ceeb nyob rau hauv daim duab.
• Astatine - tej thiab tsis tshua muaj lub ntiaj teb halogen, li ntawd, ntau yog tsis siv. Nws yog ntseeg hais tias qhov no caij yuav pab tau iodine nyob rau hauv cov kev cai ntawm lub qog cov tshuaj hormones.