Kunzwisisa Kubatana uye Mienzaniso
Pendauluan
Mukemikari, nzira iyo maatomu anobatana nayo kuti aumbe chinhu inonyanya kusarudza hunhu hwechinhu ichocho. Imwe pfungwa inokosha inotsanangura kuti maatomu anobatana sei i covalence. Covalent bonds (covalence) inowanzo kuwanikwa mumakomponi anoumbwa nezvinhu zvisiri zvesimbi, semuenzaniso mumvura (H₂O), kabhoni dioxide (CO₂), methane (CH₄), uye makemikari akasiyana-siyana ari hwaro hwehupenyu. Kunzwisisa zvinoreva covalence nemienzaniso zvichatibatsira kunzwisisa kuti maumbirwo emamorekuru anoumbwa sei, nei zvimwe zvinhu zvine mamwe mapoinzi ekufashaira, nei mamwe makomponi achinyungudika nyore nyore mumvura, uye kuti reactivity yemakemikari inoitika sei.
Kunzwisisa Kubatana
Covalence ipfungwa ine chekuita nekuumbwa kwezvisungo zvecovalent, izvo zviri zvisungo zvemakemikari zvinoitika kana maatomu maviri akagovana maerekitironi maviri kuti awane kugadzikana. Kazhinji, maatomu anoda kuwana chimiro cheelectron chakasimba senge magasi akanaka (octet rule), ayo ane maerekitironi masere mugoko rawo rekunze (kunyange zvazvo paine zvimwe zvisingawanzoitiki). Nekuti maatomu asiri esimbi anowanzova nemagetsi akawandisa uye "haarasike nyore" maerekitironi, nzira inonyanya kukosha yekuwana kugadzikana ndeyekugovana maerekitironi, pane kupa kana kugamuchira zvizere sezvakaita muzvisungo zveionic.
Nemamwe mashoko, nepo muma ionic bonds maerekitironi anotamiswa kubva paatomu imwe kuenda kune imwe, muma covalent bonds maerekitironi anogovaniswa. Ma shared electron anoumba bonding electron pair, iyo "inosunga" ma atomic nuclei maviri pamwe chete kuti igadzire molecule imwe chete kana covalent bond.
Sei Zvisungo zveCovalent Zvichiitika?
Ma "covalent bonds" anoitika nekuda kwesimba rekuti asvike padanho resimba rakaderera uye rakagadzikana. Kana maatomu maviri akasangana, ma "valence electrons" awo anogona kugoverwa, zvichiita kuti zviite sekunge atomu rega rega "rine" huwandu hwakakwana hwema "electrons" mugoko rayo rekunze. Izvi zvinoita kuti system ive yakasimba kupfuura kana maatomu akamira ega.
Semuenzaniso, atomu rehydrogen (H) rine erekitironi rimwe chete uye rinoda kugadzikana sezvakaita helium (He) nemaerekitironi maviri. Maatomu maviri ehydrogen anogona kugovana maerekitironi maviri, zvichigadzira molekyuru yeH₂. Atomu yega yega yeH₂ yava "kunzwa" sekunge ine maerekitironi maviri mugoko rayo rekutanga, nokudaro ichiwana kugadzikana.
Mhando dzeCovalent Bonds
Mabond eCovalent anogona kusiyaniswa zvichienderana nehuwandu hwemaerekitironi maviri akagoverwa pamwe chete uye zvakare zvichibva pamusiyano uripo pakati pemaatomu eelectronegativity.
1. Zvichibva pahuwandu hwemaerekitironi maviri akagovaniswa
1. Chisungo che covalent chimwe chete: kugovera maerekitironi maviri.
Muenzaniso: H—H muH₂, kana C—H muCH₄.
2. Chisungo che covalent chakapetwa kaviri: kugovana maerekitironi maviri.
Muenzaniso: O=O muO₂, kana C=O muCO₂.
3. Chisungo che covalent katatu: kugovana maerekitironi matatu.
Muenzaniso: N≡N paN₂.
Kana maerekitironi maviri akagovaniswa kakawanda, chisungo chacho chinosimba uye daro riri pakati pemaatomu rinova pfupi.
2. Zvichibva pa polarity
1. Zvisungo zve covalent zvisiri zvepolar
Zvinoitika kana maatomu ese ari maviri aine maelectronegativities akafanana kana akafanana, zvekuti maerekitironi maviri anogovaniswa zvakaenzana.
Muenzaniso: H₂, O₂, N₂, Cl₂.
2. Zvisungo zve polar covalent
Izvi zvinoitika kana musiyano we electronegativity wakakosha zvakakwana zvekuti electron pair inokwezvwa zvakanyanya kune rimwe reatomu. Izvi zvinoguma ne partial charges (δ⁺ uye δ⁻).
Mienzaniso: H—Cl muHCl, O—H muH₂O.
Zvakakosha kusiyanisa kuti polar bond hairevi nguva dzose kuti molecule iri polar; polarity yemorekuru inopesvedzerwawo nechimiro chemorekuru (geometry).
Mienzaniso yeCovalence muMakomputa Ezuva Nezuva
Heano mimwe mienzaniso iri nyore kuwana muhupenyu hwezuva nezuva:
1. Mvura (H₂O)
Mvura muenzaniso wakakosha wechinhu chine polar covalent bonds. Atomu yeokisijeni ine electronegative kupfuura hydrogen, saka lone pair inokwezvwa zvakanyanya neokisijeni. Izvi zvinopa mvura hunhu hwakasiyana hwakadai sekukwanisa kwayo kunyungudutsa zvinhu zvakawanda, kumanikidzwa kwepamusoro, uye kufashaira kwakanyanya kana tichienzanisa nemamwe mamorekuru madiki.
MuH₂O, kune mabhondi maviri epolar O—H. Pamusoro pezvo, chimiro che "bent" (kwete linear) chemamorekuru emvura zvinoreva kuti nguva dzavo dze dipole hadzisiyane, saka mamorekuru emvura ese ari polar.
2. Kabhoni dhayokisaidhi (CO₂)
CO₂ ine ma bond maviri e covalent ari pakati paC naO (O=C=O). C=O bond iri polar, asi CO₂ ine linear, saka ma dipole moments ayo maviri anodzimana. Nekuda kweizvozvo, CO₂ molecule haina polar zvachose. Ichi ndicho chimwe chikonzero nei CO₂ isinganyungudike zvakanyanya mumvura pane zvinhu zvepolar zvakachena, kunyangwe ichigona kuita reactive kuumba carbonic acid pasi pemamwe mamiriro ezvinhu.
3. Methane (CH₄)
Methane chinhu chiri nyore cheorganic chinoumbwa nezvisungo zve covalent zviri pakati peC neH. Kazhinji, CH₄ haina polar nekuti chimiro chayo chakaenzana ne tetrahedral uye musiyano we electronegativity uripo pakati peC neH hauna kukura zvakanyanya. Methane ndiyo chinhu chikuru chegasi rechisikigo uye inoshandiswa zvakanyanya semafuta.
4. Okisijeni (O₂) neNitrogen (N₂)
O₂ ine chisungo che covalent chakapetwa kaviri (O=O), nepo N₂ ine chisungo che covalent chakapetwa katatu (N≡N). Chisungo che triple chakapetwa katatu muN₂ chakasimba zvikuru, zvichiita kuti nitrogen isashande zvakanaka (haishande zviri nyore) mumamiriro ezvinhu akajairwa. Ndosaka nitrogen ichitonga mhepo yepasi asi isingaite zviri nyore pasina mamiriro chaiwo kana rubatsiro rwe catalyst.
5. Hydrogen chloride (HCl)
HCl muenzaniso we polar covalent bond. Chlorine (Cl) ine electronegative kupfuura hydrogen, saka maerekitironi ayo anokwezvwa zvakanyanya neCl, zvichikonzera chikamu chekuchaja. Kana yanyungudutswa mumvura, HCl ionizes kuti igadzire H⁺ naCl⁻, zvichiita kuti izive strong acid. Izvi zvinoratidza kuti compound inogona kuva necovalent bond asi ichigadzira maion mu solution.
6. Amoniya (NH₃)
Ammonia ine chisungo che covalent pakati peN neH. Molekyuru yeNH₃ ine chimiro chetrigonal pyramidal uye ine polar. Ammonia inoshandiswa zvakanyanya muindasitiri yefetereza, kuchenesa, uye maitiro akasiyana-siyana emakemikari. Polarity yeAmmonia inoita kuti ishande nesimba nemvura.
Hunhu Hwakazara hweCovalent Compounds
Kazhinji, makemikari e covalent ane hunhu hunotevera (kunyange zvazvo paine zvimwe zvakasiyana):
1. Mazhinji anoumbwa nezvinhu zvisiri zvesimbi.
2. Kazhinji dzine poindi shoma dzekunyunguduka nekudzikira kupfuura ma ionic compounds, kunyanya kumamorekuru madiki.
3. Makemikoro asina polar covalent anowanzo nyungudika mumvura, asi anonyungudika muzvinhu zvisinganyungudike.
4. Usafambisa magetsi uri muchimiro chakasimba; mimwe inogona kufambisa magetsi kana ikaitwa ion mumusanganiswa (semuenzaniso HCl mumvura).
5. Inowanikwa muzvinhu zvakawanda zve organic zvakaita se hydrocarbons, alcohols, organic acids, uye mapuroteni.
Penutup
Covalence ipfungwa huru inotsanangura kuti maatomu, kunyanya nonmetals, anoumba sei bonds nekugovana maerekitironi maviri. Covalent bonds inogona kuva imwe chete, mbiri, kana katatu, uye inogona kuva polar kana nonpolar. Mienzaniso inozivikanwa zvikuru muhupenyu hwezuva nezuva, senge mvura (H₂O), kabhoni dioxide (CO₂), methane (CH₄), okisijeni (O₂), nitrogen (N₂), uye hydrogen chloride (HCl). Nekunzwisisa tsananguro ye covalence nemienzaniso, tinogona kubatanidza zviri nyore chimiro chemamorekuru nehunhu hwemuviri uye hwemakemikari hwechinhu.
Kana muchida, ndinogona kuwedzera chinyorwa chine ruzivo rwesainzi (nehurukuro yemaumbirwo eLewis, mutemo weoctet, uye molecular geometry) kana shanduro iri nyore yevadzidzi vechikoro chesekondari.
