Sarudza valence yemakemikari ezvinhu

Izvo ruzivo rwechimiro cheatomu nemamolekoro muzana remakore rechiXIX harina kutitendera kuti titsanangure chikonzero nei maatomu akaumba imwe nhamba yezvisungo nezvimwe zvikamu. Asi pfungwa dzevasayendisiti dzakapedza nguva yavo, uye valency ichiri kuongororwa seimwe yemitemo inokosha yemakemikari.

Kubva munhoroondo yemugariro we "valence yemakemikari ezvinhu"

Imwe nyanzvi yekuChirungu yemakemikari yezana remakore rechi19, Edward Frankland, akaisa shoko rokuti "kubatana" mukushandiswa kwesayenzi kurondedzera kubatana kweatomu pamwe chete. Musayendisiti akacherechedza kuti zvimwe zvikamu zvemakemikari zvinoumba zvinosanganisira nhamba imwechete yeimwe maatomu. Semuenzaniso, nitrogen inowedzera matatu maatomu e-hydrogen kumamonia molecule.

MunaMay 1852, Frankland akafungidzirwa kuti pane nhamba chaiyo yemakemikisitiri akasungwa iyo atomu inogona kuumba nezvimwe zviduku zviduku. Frankland akashandisa mutsara wokuti "kushanda nesimba" kurondedzera izvo zvaizozonzi "valency". Mukati wemakemikari weBrithani akasimbisa kuti mangani emakemikari akasungirirwa akaita maatomu ezvimwe zvinhu zvinowanikwa pakati pezana remakore rechina. Basa reFrankland rava mupiro unokosha kumagadzirirwo emakemikari emazuva ano.

Kuvandudza maonero

German chemist F.A. Kekule akaratidza muna 1857 kuti kabhoni ichina-msingi. Mukushamwaridzana kwayo kwakajeka - methane - kune kubatana ne 4 hydrogen atomu. Izwi rokuti "basicity" musayendisiti akashandisa kugadzirisa zvinhu zvezvinhu kuti asungirire nhamba yakanyatsorondedzerwa yezvimwe zvikamu. MuRussia, dhesi pamusoro pekugadzirisa nyaya yacho yakagadziriswa na AM Butlerov (1861). Kuwedzera kwekuvandudza kwenyanzvi yekubatanidza makemikari kwaive nekuda kwenheyo ye periodic change muzvinhu zvezvinhu. Munyori waro ndeimwezve nyanzvi yekuRussia yemakemikari, DI Mendeleev. Akaratidza kuti valence yemakemikari zvinhu mumakemikari nezvimwe zvinhu zvinokonzerwa nechinzvimbo chavanoita mu periodic system.

Chimiro chekufananidzira kwehutano uye makemikari ekubatanidza

Mikana yekutarisa kwema molecules ndeimwe yezvisina mubvunzo zvinotarisirwa zvevheti yepamusoro. Mhando yekutanga yakabuda muma 1860, uye kubva muna 1864 maitiro ekushandiswa anoshandiswa ayo anotenderera nechiratidzo chekemikari mukati. Pakati pezviratidzo zveatomu dash inoreva chimiro chemakemikari, uye nhamba yemiganhu iyi yakaenzana nekukosha kwevhiriji. Mumakore mamwe chete, mazana ekutanga-bhora-uye-rod akabudiswa (ona mufananidzo kuruboshwe). Muna 1866, Kekule akaronga mutsara we stereochemical weatomu yekodhi mumutauro we tetrahedron, waakanyora mubhuku rake rinonzi "Organic Chemistry."

Iyo valeni yemakemikari ezvo uye kubuda kwekubatana kwakadzidzwa naG. Lewis, uyo akabudisa basa rake muna 1923 mushure mekuwanikwa kwe electron. Izvozvo zvinodanwa zvisina kunaka zvidhinhwa zviduku zviduku, izvo zvikamu zvehombodo dzeatomu, zvinodanwa. Mubhuku rake, Lewis akashandisa nharo dzakapoteredza kumativi mana echiratidzo chekemikari chinhu chinomirira valence electrons.

Valence ye hydrogen uye oksijeni

Pamberi pekusika kwe periodic system, valence yemakemikari zviri mumakemikari akatorwa kufananidzwa neaya maatomu ayo anozivikanwa. Sezvinodiwa, hydrogen uye oksijeni zvakasarudzwa. Chimwe chemikemikari chinokwezva kana kutsiva imwe nhamba yeH atomu nei O.

Nenzira iyi, dzimba dzakagadziriswa mumakemikari ne monovalent hydrogen (iyo valeni yechipiri chinhu chinotarisirwa neRoma chiverengero):

• HCl - chloro (I):
• H ₂ O-oksijeni (II);
• NH ₃ - nitrogen (III);
• CH ₄ - kabhoni (IV).

Mu (O), K (I), C (II), N (III) Muchidimbu yeOxy ₂ , CO, N ₂ O ₃ , SiO ₂ , SO ₃ , , Si (IV), S (VI).

Nzira yekuziva sei valence yemakemikari zvinhu

Iko kune nguva dzose mukugadzirwa kwekemikisi kubatanidza inowanzobatana pamagetsi emagetsi:

• Izvo zvinonzi hydrogen valence ndiI.
• Iyo inowanzo oksijeni valence i II.
• Nokuda kwezvinhu zvisingaenzaniswi, valence yakaderera inogona kutsanangurwa nemaitiro 8 - nhamba yeboka ravari mune tafura ye periodic. Ipamusoro, kana zvichibvira, inotsanangurwa neboka reboka.
• Pamusoro pezvikamu zvegutsana, huwandu hwehutano hunogona kuenzana nehuwandu hweboka ravo mutafura ye periodic.

Kutsunga kwevhiriji yemakemikari nemagadzirirwo emakemikari inoitwa nekushandisa shanduro inotevera:

1. Nyora pasi pamusoro pemiti yemikemikirwo inokosha inozivikanwa yeimwe yezvinhu. Somuenzaniso, muMn ₂ O _7, valence _ye oxygen i II.
2. Verengai kukosha kwese, iyo iyo inofanirwa kuwedzera valence nehuwandu hweatomu yemamwe makemikari chinhu mu mole molecule: 2 * 7 = 14.
3. Tsanangurai valence yechipiri chechipiri iyo isingazikamwi. Gurai kukosha kunowanikwa mundima 2 nehuwandu hweatomu maMun molecule.
4. 14: 2 = 7. Valence ye manganese mumakisi ayo yakakwirira ndeyeVII.

Constant uye variable valence

Maitiro e hydrogen uye oksijeni akasiyana. Semuenzaniso, sulfure mukombani H ₂ S inonzi divalent, uye mu formula SO ₃ - hexavalent. Carbon inoumba oksijeni CO monoxide uye CO ₂ dioxide. Muchikamu chekutanga, valeni yeC is II, uye muchipiri, IV. Izvo zvinokosha mu methane CH ₄ .

Zvizhinji zvezvinhu hazviratidzi nguva dzose, asi inoshandiswa valence, somuenzaniso, phosphorus, nitrogen, sulfur. Kutsvaga kwezvikonzero zvinokonzera chiitiko ichi kwakakonzera kubuda kwemanamato emakemikari ekubatanidza, pfungwa pamusoro pechigoni chevhiriji chema electron, orbitals molecule. Kuvapo kwemitemo yakasiyana yenzvimbo imwechete yakatsanangurwa maererano nehutano hweatomu nemamolekoro.

Nhasi pfungwa dzev valence

Maatomu ose ane nucleus yakanaka yakakomberedzwa nemasikironi anokanganisa. Iko kona yekunze, iyo yavanoita, haina kupera. Chimiro chakapedzwa ndicho chakasimba kwazvo, chaine 8 electrons (octet). Kuonekwa kwekemikisi yakabatanidzwa neyemagetsi ehurumende inowirirana inotungamirira kuhutano hwakanaka hwemaatomu.

Mutemo wekugadzirwa kwemakemikari ndeye kugadziriswa kwekombodhi kuburikidza nokutora elektrons kana kupa zvisingabatsiri, zvichienderana nekutungamira kwacho kunopfuura nyore nyore. Kana atomu inopa zvinhu zvisina kunaka zvekugadzirwa kwekemikisi, iyo isina michina, zvino inoumba sezvisungo zvakawanda sekunge pane magetsi asina kubhadhara. Maererano nemanzwiro emazuva ano, kubwinya kweatomu yemakemikari zvinhu kukwanisa kuumba imwe nhamba yezvibvumirano zvakasimba. Somuenzaniso, mune hydrogen sulfide H ₂ S molecule, sulfuri inowana valence II (-), sezvo atomu imwe inobatanidzwa mukuumbwa kwemasaroni maviri maviri. Chiratidzo "-" "chinoratidza kukwezva kwema electron maviri kune imwe nzvimbo ye electronegative element. Pachisarudzo zvisingasarudzo zvekugadzwa kwevhiriji, wedzera "+".

Nevamwe vanozvipa-vanobvuma, michina yepamagetsi yeimwe chinhu uye valent free orbitals yeimwe iyo inotora chikamu muchiito.

Kutenderera kwevhiriji pane chimiro cheatomu

Chimbofunga, somuenzaniso, kabhoni uye oksijeni, kuti valence yemakemikari zvinokonzerwa sei nekugadzirisa nyaya. Tafura yaMendeleyev inopa pfungwa yezvinhu zvikuru zveatomu yeatoni:

• Chiratidzo chemakemikari - C;
• Element nhamba 6;
• Mutoro wekasiyo +6;
• Mapurotoni ari mumusimboti - 6;
• Electrions - 6, kusanganisira 4 kunze, iyo 2 iyo inoumba pairi, 2 - isina kubhadhara.

Kana kabhoni atomu muC CO monooxyide inoumba zvibatanidza zviviri, uye chete 6 nhengo dzisina kunaka dzinoshandisa kwayo. Kuti uwane octet, zvakakosha kuti maviri acho aite 4 kunze kwenhengo dzisina kunaka. Carbon ine valence ye IV (+) mu dioxide uye IV (-) mumethane.

Nhamba yeodinini ye oksijeni ndeye 8, ganda revaji rino rine magetsi matanhatu, 2 ayo haaiti mapaundi uye anotora chikamu kusungirirana nekubatana nemamwe maatomu. Iyo inowanzo oksijeni valence i II (-).

Valence uye oxidation nyika

Muzviitiko zvakawanda kwazvo zviri nyore kushandisa izwi rokuti "oxyidation state". Iri ndiro zita rekutengesa kweatomu, iyo inogona kuwana kana magetsi ose akasungirirwa akaendeswa kune chimwe chinhu chinonyanya kukosha kwe electronegativity (EO). Iyo nhamba ye oxidzing muzvinhu zvisiri nyore zero. Kusvika kwehuwandu hwekushandiswa kwehutano kupfuura EO yezvinhu zvinowedzera chiratidzo "-", zvishoma pasi electronegative - "+". Semuenzaniso, kune zvigadzirwa zvemasimba makuru, maidhijidhi ejairiri uye ion mashandiro akaenzana nenhamba yeboka rine chiratidzo "+". Muzviitiko zvakawanda, valence uye chidimbu chekushandiswa kweatomu muatomu imwe chete inowanzofanana. Chero bedzi pakubatanidzwa nemamwe maatomu e electronegative ndeyero yeiyoiyoiyo yakanaka, uye zvinhu izvo EO iri pasi, hazvina kunaka. Izwi re "valency" rinowanzoshandiswa chete kune zvinhu zvemaoremendi.