Yuav ua li cas yog cov pa? oxygen tebchaw

Pa (O) - uas tsis yog-nws yog xim hlau tshuaj caij ntawm cov pab pawg neeg 16 (ntawm) ntawm lub Periodic rooj. Nws yog ib tug tsis muaj kob, mov thiab ntxhiab pa roj yuav tsum tau rau muaj sia nyob - tsiaj uas hloov nws mus rau hauv cov pa roj carbon dioxide, thiab cov nroj tsuag uas siv CO ₂ raws li ib tug carbon qhov twg los, thiab O ₂ yog rov qab mus rau lub ntuj kaaj quas lug. Pa ntaub ntawv ib tug compound reacting nrog zoo yam lwm lub caij, thiab displaces cov tshuaj hais ntawm kev sib txuas lus nrog rau ib leeg. Nyob rau hauv Feem ntau, cov dab yuav nrog qhov kev tso tawm ntawm tshav kub thiab lub teeb. Qhov tseem ceeb tshaj compound ntawm oxygen yog dej.

Keeb kwm ntawm foundations

Nyob rau hauv 1772, lub Swedish chemist Carl Wilhelm Scheele thawj pom hais tias nws hais tias xws li cov pa uas tau txais nws los ntawm cov cua kub nitrate poov tshuaj oxide, mercury, raws li zoo raws li ntau lwm yam. Ntawm nws tus kheej ntawm nws nyob rau hauv 1774, ib tug English chemist Dzhozef Pristli sab cov tshuaj caij los ntawm thermal decomposition ntawm mercury oxide thiab luam tawm nws tshawb pom nyob rau hauv tib lub xyoo, peb lub xyoos ua ntej Scheele ntawv. Nyob rau hauv lub xyoo 1775-1780 rau hauv lub Fabkis chemist Antuan Lavuaze txhais lub luag hauj lwm ntawm cov pa nyob rau hauv lub ua tsis taus pa thiab burning, muab pov tseg rau hauv lub phlogiston kev tshawb xav, feem ntau txais thaum lub sij hawm. Nws yog muab sau rau nws ib txwm mus tsim acids thaum ua ke nrog ntau yam tshuaj thiab hu ua oxygène caij, uas nyob rau hauv Greek txhais hais tias "generated acid".

loj heev

Yuav ua li cas yog cov pa? Ris rau 46% los ntawm qhov hnyav ntawm lub kiav txhab, nws yog feem ntau ntawm nws cov ntsiab. Tus nqi ntawm cov pa nyob rau hauv cov cua yog 21% los ntawm lub ntim thiab tus luj ntawm nws 89% nyob rau hauv seawater.

Nyob rau hauv cov pob zeb caij nrog lub co thiab uas tsis yog-hlau li cov oxides uas yog acidic (e.g., sulfur, carbon, txhuas, thiab phosphorus) los yog yooj yim (calcium, magnesium thiab hlau) thiab raws li ib tug ntsev zoo li tebchaw uas muaj peev xwm yuav ntshai li tsim los ntawm acid thiab yooj yim oxides xws li sulfates, carbonates, silicates, phosphates thiab aluminates. Txawm tias lawv yog heev heev, tab sis cov no khib nyiab pab tsis tau raws li cov pa qhov chaw, raws li daim ntawv cog lus cleavage nrog hlau caij atoms zog noj ib yam nkaus thiab.

nta

Yog hais tias cov pa kub hauv qab no -183 ° C, nws yuav daj ntseg xiav kua, thiab nyob -218 ° C - khoom. Ntshiab O ₂ yog 1.1 lub sij hawm hnyav zog dua cov pa.

Thaum lub sij hawm ua tsis taus pa tsiaj thiab ib co kab mob haus cov pa los ntawm cov cua thiab siv cov pa roj carbon dioxide, whereas nyob rau hauv ntsuab tsob nroj photosynthesis nyob rau hauv lub xub ntiag ntawm tshav ntuj nqus cov pa roj carbon dioxide thiab tso free oxygen. Ze li ntawm tag nrho cov O ₂ nyob rau hauv cov cua yog ua los ntawm photosynthesis.

Nyob rau hauv 20 ° C rau txog 3 qhov chaw los ntawm lub ntim ntawm cov pa yaj nyob rau hauv 100 qhov chaw ntawm cov dej tshiab, ib tug me ntsis tsawg tshaj - nyob rau hauv seawater. Nws yog tsim nyog rau kev ua pa ntawm ntses thiab lwm yam marine lub neej.

Ntuj oxygen yog ib tug sib tov ntawm peb ruaj khov isotopes ¹⁶ O (99,759%), ¹⁷ O ^(0,037%), thiab ¹⁸ O (0,204%). Muaj ntau ntau artificially ua tej isotopes. Feem ntau ntawm lawv yog ntev-nyob yog ¹⁵ O (ib nrab-lub neej 124) uas yog siv rau kev kawm ua pa nyob rau hauv ib tug muaj plaub.

allotrope

Ib tug dlaim phaj tswv yim dab tsi oxygen, cia kom tau nws ob tug allotropic cov ntaub ntawv, diatomic (O ₂₎ thiab triatomic (O _3, ozone). Properties diatomic daim ntawv hais tias rau electrons khi atoms thiab ob nyob twj ywm unpaired, ua rau cov paramagnetism ntawm oxygen. Peb atom ozone molecules tsis nyob rau ntawm ib txoj kab ncaj nraim.

Nws yuav tau ua nyob rau hauv raws li cov kab zauv: 3O ₂ → 2O _3.

Tus txheej txheem yog endothermic (yuav tsum tau zog); hloov dua siab tshiab ntawm ozone rov qab mus rau hauv diatomic oxygen txhawb mus rau ntawm txoj kev hloov co los yog lawv oxides. Ntshiab oxygen yog hloov dua siab tshiab rau hauv ozone los ntawm qhov kev txiav txim ntawm ib tug hluav taws xob glow tawm. Cov tshuaj tiv thaiv kuj tshwm sim raws li qhov haum ntawm ultraviolet lub teeb nrog ib tug wavelength ntawm txog 250 nm. Cov tshwm sim ntawm txoj kev no nyob rau sab qaum cua eliminates tawg uas yuav muaj teeb meem rau lub neej nyob rau ntawm qhov chaw ntawm lub ntiaj teb. Pungent tsw ntawm ozone yog tam sim no nyob rau hauv tsev nrog ib tug sparking hluav taws xob khoom xws li generators. Qhov no gas yog lub teeb xiav. Nws ceev ntawm 1.658 lub sij hawm ntau tshaj rau saum huab cua, thiab muaj ib tug kub point ntawm -112 ° C nyob atmospheric siab.

Nws - muaj zog oxidant muaj peev xwm hloov leej faj dioxide, trioxide, sulfide rau sulfate, iodide, iodine (analytical txoj kev muab nws cov kev ntsuam xyuas) raws li muaj ntau yam pa uas muaj organic compound derivatives xws li aldehydes thiab acids. Conversion ntawm hydrocarbons nrog ozone los ntawm tsheb cov pa tso gases nyob rau hauv cov acids thiab aldehydes yog qhov ua rau ntawm smog. Nyob rau hauv kev lag luam, ozone yog siv raws li ib tug tshuaj reactant, tshuaj tua kab mob rau dej kev kho mob, dej purification thiab tshuaj dawb tso ntawm fabrics.

txoj kev ntawm kev npaj

Txheej txheem rau cov oxygen nyob rau ntau npaum li cas cov roj yuav tsum tau txais. Kuaj cov hau kev rau tus nram qab no:

1. Thermal decomposition ntawm ib co ntsev xws li poov tshuaj chlorate los yog poov tshuaj nitrate:

• 2KClO ₃ → 2KCl + 3O _2.
• 2KNO ₃ → 2KNO ₂ + O _2.

Poov tshuaj chlorate decomposition tshwmsim los ntawm txoj kev hloov hlau oxides. Rau qhov no feem ntau siv manganese dioxide (pyrolusite, MnO _2). Lub catalyst txo qhov kub thiab txias yuav tsum tau rau cov pa evolution, los ntawm 400 rau 250 ° C.

2. Degradation ntawm cov hlau oxides nyob rau hauv qhov kev txiav txim ntawm kub:

• 2HgO → 2Hg + O _2.
• 2Ag ₂ O → 4Ag + O _2.

Scheele thiab Priestley rau no tshuaj caij siv compound (oxide), cov pa thiab mercury (II).

3. Cov thermal decomposition ntawm cov hlau peroxides los yog hydrogen peroxide:

• 2BaO + O ₂ → 2BaO _2.
• ₂ 2BaO → 2BaO + O _2.
• Bao ₂ + H ₂ li ₄ → H ₂ O ₂ + BaSO _4.
• 2H ₂ O ₂ → 2H ₂ O + O _2.

Tus thawj muaj txoj kev rau kev sib cais ntawm cov pa los ntawm cov cua los yog rau zus tau tej cov hydrogen peroxide nyob ntawm seb lub tsim ntawm ib tug oxide ntawm barium peroxide.

4. electrolysis dej nrog me me admixtures ntawm ntsev los yog acids uas muab conduction ntawm hluav taws xob tam sim no:

2H ₂ O → 2H ₂ + O ₂

muaj ntau lawm

Yog hais tias tsim nyog los tau loj nyiaj ntawm cov pa yog siv fractional distillation ntawm cov kua cua. Ntawm tus loj Cheebtsam ntawm huab cua nws muaj lub siab tshaj plaws kub kub thiab yog li ntawd, muab piv rau nitrogen, thiab tsawg volatile argon. Cov txheej txheem siv ib tug txias roj thaum lub sij hawm nws expansion. Lub ntsiab theem ntawm lub lag luam raws li nram no:

• huab cua yog lim kom tshem tawm cov khoom hais;
• ya raws thiab cov pa roj carbon dioxide raug muab tshem tawm los ntawm haum nyob rau hauv alkali;
• huab cua yog compressed thiab cov compression thaum tshav kub kub yog muab tshem tawm los ntawm cov pa txheej txheem cua txias;
• ces nws nkag mus rau mus rau hauv lub kauj nyob rau hauv lub chamber;
• ib feem ntawm lub compressed roj (ntawm ib tug siab ntawm 200 txog atm) nyob rau hauv lub chamber expands, cua txias rau lub kauj;
• txhab roj rov qab mus rau lub compressor thiab kis tau los ntawm ob peb theem ntawm compression thiab tom ntej expansion, uas nyob rau ntawm lub -196 ° C, cov huab cua yuav kua;
• rhuab kua distillation thawj lub teeb inert gases, ces nitrogen thiab kua oxygen seem. Ntau fractionation ua ib yam khoom txaus dawb huv (99.5%) rau feem ntau muaj daim ntaub ntawv.

Siv nyob rau hauv kev lag luam

Co qhov loj tshaj plaws neeg ntshiab oxygen rau zus tau tej cov high-carbon steel: tshem ntawm cov pa roj carbon dioxide thiab lwm yam uas tsis yog-metallic impurities vim hais tias cuam sai thiab yooj yim tshaj nrog cua.

Dej Khib Nyiab oxygen cog lus rau ntau npaum tuav ntawm cov kua effluent tshaj nyob rau hauv lwm yam tshuaj dab. Nws yog ua nce tseem ceeb heev nyob rau hauv kaw pov tseg incineration systems siv ntshiab O _2.

Lub thiaj li hu ua missile oxidizer yog kua oxygen. Ntshiab O ₂ Qhov no yog siv nyob rau hauv submarines thiab nyob rau hauv lub dhia tswb.

Nyob rau hauv lub tshuaj kev lag luam, cov pa hloov zoo tib yam huab cua nyob rau hauv zus tau tej cov tshuaj xws li acetylene, ethylene oxide thiab methanol. Kev kho mob daim ntaub ntawv muaj xws li kev siv cov oxygen gas nyob rau hauv lub lag tshuaj txau thiab tus me nyuam incubators. kev ua kom loog roj enriched nrog cov pa muab lub neej pab txhawb nqa thaum lub sij hawm ua kom tsaug zog. Qhov no tsis muaj tshuaj caij tau nyob ua ib ke ib tug xov tooj ntawm industries uas siv furnaces. Hais tias yog dab tsi oxygen.

Cov tshuaj zog thiab cov tshuaj tiv thaiv

Loj qhov tseem ceeb ntawm electron affinity thiab electronegativity ntawm oxygen yog raug cheebtsam uas muaj nws yog xim hlau zog. Tag nrho cov tebchaw muaj tsis zoo pa oxidation lub xeev. Thaum ob tug electron orbitals sau, tsim O ^2- ion. Lub peroxides (O ₂ ^2-) assumes uas txhua atom muaj ib tug saib xyuas ntawm -1. Qhov no cov khoom teejtug uas txais electrons los ntawm ib tug tag nrho los yog ib nrab kis tau tus mob thiab txiav txim ib tug oxidizing neeg sawv cev. Thaum tus neeg saib xyuas reacts nrog cov tshuaj yeeb dej caw, electron pub, nws tus kheej oxidation lub xeev lawm. Cov kev hloov (txo) nyob rau hauv cov pa oxidation lub xeev ntawm xoom kom -2 hu ua rov qab.

Nyob rau hauv tej yam kev mob rau lub caij tas ib dihydric thiab trihydric tebchaw. Nyob rau hauv tas li ntawd, muaj yog tsis tshua muaj tsis ruaj tsis khov molecules chetyrehatomnye. Nyob rau hauv diatomic daim ntawv ob unpaired electrons muaj nyob rau ntawm lub nonbonding orbitals. Qhov no tus cwj pwm yog paub tseeb hais tias los ntawm ib tug paramagnetic roj.

Khaus reactivity yog tej zaum piav ozone assumption tias ib tug ntawm peb cov atoms yog nyob rau hauv lub "atomic" lub xeev. Reacting no atom yog dissociated los ntawm lub O _3, tawm hauv molecular oxygen.

O ₂ molecule ntawm ib txwm kub thiab ambient siab weakly reactive. Lub atomic oxygen yog ntau npaum li cas kom nquag plias. Lub dissociation zog (O ₂ → 2O) tseem ceeb thiab yog 117,2 kcal ib tus nas.

kev sib txuas

C xws nonmetals li hydrogen, carbon, sulfur, oxygen, cov ntaub ntawv ib tug loj ntau ntawm cov covalently ua txhua yam sib txuas, xws li nonmetal oxides xws li dej (H ₂ O), sulfur dioxide (LI NTAWD ₂₎ thiab cov pa roj carbon dioxide (CO _2); organic tebchaw xws li alcohols, aldehydes thiab carboxylic acids; ntau acids xws li carbonic _{(H2 CO3),} sulfuric acid (H ₂ li ₄₎ thiab nitric (HNO _3); thiab cov coj ntsev, xws li sodium sulfate (Na ₂ li _4), sodium carbonate (Na ₂ CO ₃₎ thiab sodium nitrate (nano _3). Pa yog tam sim no nyob rau hauv daim ntawv ntawm O ^2- ion nyob rau hauv lub siv lead ua qauv ntawm cov khoom hlau oxides, xws li compound (oxide), cov pa thiab Cao ntawm calcium. Hlau superoxide (KO ₂₎ muaj ion O ₂ ^-, thaum hlau peroxides (Bao ₂₎ muaj ion O ₂ ^2-. oxygen tebchaw feem ntau muaj ib tug -2 oxidation lub xeev.

Ntsiab zog

Thaum kawg peb sau cov ntsiab thaj chaw ntawm pa:

• Electron configuration: 1s 2s ^{2 2} 2p ^4.
• Atomic tooj: 8.
• Atomic loj: 15,9994.
• Kub point: -183,0 ° C.
• Melting point: -218,4 ° C.
• Ceev (yog hais tias tus oxygen siab yog 1 atm ntawm 0 ° C): 1.429 g / l.
• oxidation lub xeev ntawm -1, -2, +2 (nyob rau hauv lub tebchaw nrog fluorine).