Carl Scheele, katswiri wa zamankhwala wa ku Sweden, ndi Daniel Rutherford, katswiri wa zomera wa ku Scotland, anapeza nayitrojeni mosiyana mu 1772. M’busa Cavendish ndi Lavoisier nawonso analandira nayitrojeni paokha pa nthawi yomweyo. Nayitrojeni adadziwika koyamba ndi Lavoisier, yemwe adatcha "azo", kutanthauza "wopanda moyo". Chaptal adatcha element nitrogen mu 1790. Dzinali limachokera ku liwu lachi Greek "nitre" (nitrate yomwe ili ndi nayitrogeni mu nitrate).
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Magwero a Nayitrogeni
Nayitrogeni ndiye chinthu cha 30 chomwe chili ndi mphamvu zambiri padziko lapansi. Poganizira kuti nayitrogeni amapanga 4/5 ya voliyumu ya mumlengalenga, kapena kupitilira 78%, tili ndi kuchuluka kwa nitrogen kosawerengeka kwa ife. Nayitrojeni imapezekanso mu mawonekedwe a nitrates mumitundu yosiyanasiyana ya mchere, monga Chile saltpeter (sodium nitrate), saltpeter kapena nitre (potaziyamu nitrate), ndi mchere wokhala ndi ammonium salt. Nayitrojeni amapezeka m'mamolekyu ambiri ovuta, kuphatikizapo mapuloteni ndi amino acid omwe amapezeka m'zamoyo zonse.
Thupi katundu
Nayitrojeni N2 ndi mpweya wopanda mtundu, wopanda fungo, wopanda fungo komanso wopanda fungo ndipo nthawi zambiri umakhala wopanda poizoni. Kuchuluka kwa gasi pansi pazikhalidwe zokhazikika ndi 1.25g/L. Nayitrojeni amawerengera 78.12% ya mlengalenga wonse (gawo la voliyumu) ndipo ndiye gawo lalikulu la mpweya. Mumlengalenga muli matani pafupifupi 400 thililiyoni a mpweya.
Pansi pa kuthamanga kwa mumlengalenga, kukazizira mpaka -195.8 ℃, kumakhala madzi opanda mtundu. Ikazizira mpaka -209.86 ℃, nayitrogeni yamadzimadzi imakhala yolimba ngati chipale chofewa.
Nayitrojeni sangapse ndi moto ndipo amatengedwa ngati mpweya woziziritsa thupi (mwachitsanzo, kupuma kwa nayitrogeni woyera kumalepheretsa thupi la munthu mpweya). Nayitrogeni ali ndi kusungunuka kochepa kwambiri m'madzi. Pa 283K, voliyumu imodzi yamadzi imatha kusungunuka pafupifupi ma voliyumu 0.02 a N2.
Mankhwala katundu
Nayitrogeni ali ndi mankhwala okhazikika. Zimakhala zovuta kuchita ndi zinthu zina kutentha kwa chipinda, koma zimatha kusintha kusintha kwa mankhwala ndi zinthu zina pansi pa kutentha kwakukulu ndi mphamvu zambiri, ndipo zingagwiritsidwe ntchito kupanga zinthu zatsopano zothandiza kwa anthu.
Mamolekyulu a orbital a mamolekyu a nayitrogeni ndi KK σs2 σs*2 σp2 σp*2 πp2. Magulu atatu a ma electron amathandizira kuti agwirizane, ndiye kuti, ma bond awiri a π ndi imodzi σ chomangira amapangidwa. Palibe chothandizira pakugwirizanitsa, ndipo mphamvu zomangira ndi zotsutsana ndi zotsutsana zatsala pang'ono kuthetsa, ndipo ndizofanana ndi ma electron awiriawiri. Popeza pali chomangira katatu N≡N mu molekyulu ya N2, molekyulu ya N2 imakhala yokhazikika, ndipo zimatengera 941.69 kJ/mol mphamvu kuti iwononge kukhala maatomu. Molekyu ya N2 ndiyokhazikika kwambiri mwa mamolekyu odziwika bwino a diatomic, ndipo ma molekyulu a nayitrogeni ndi 28. Komanso, nayitrogeni siwosavuta kuwotcha ndipo sichirikiza kuyaka.
Njira yoyesera
Ikani Mg bar yoyaka mu botolo lotolera gasi lodzaza ndi nayitrogeni, ndipo Mg bar ipitilira kuyaka. Chotsani phulusa lotsalalo (ufa wachikasu pang'ono Mg3N2), onjezerani madzi pang'ono, ndikutulutsa mpweya (ammonia) womwe umasintha pepala lonyowa lofiira la litmus kukhala buluu. Rection equation: 3Mg + N2 = poyatsira = Mg3N2 (magnesium nitride); Mg3N2 + 6H2O = 3Mg (OH) 2 + 2NH3↑
Makhalidwe a mgwirizano ndi kapangidwe ka valence bond ya nayitrogeni
Chifukwa chinthu chimodzi cha N2 chimakhala chokhazikika kwambiri m'malo abwinobwino, anthu nthawi zambiri amakhulupirira molakwika kuti nayitrogeni ndi chinthu chosagwira ntchito ndi mankhwala. M'malo mwake, m'malo mwake, elemental nayitrogeni imakhala ndi zochita zambiri zamakina. Electronegativity ya N (3.04) ndi yachiwiri kwa F ndi O, kusonyeza kuti ikhoza kupanga zomangira zolimba ndi zinthu zina. Kuphatikiza apo, kukhazikika kwa molekyulu imodzi ya N2 kumangowonetsa ntchito ya atomu ya N. Vuto ndilakuti anthu sanapezebe mikhalidwe yoyenera kuyambitsa mamolekyu a N2 kutentha ndi kupanikizika. Koma m'chilengedwe, mabakiteriya ena pamagulu a zomera amatha kusintha N2 mumlengalenga kukhala mankhwala a nayitrogeni pansi pamikhalidwe yotsika mphamvu pa kutentha ndi kupanikizika, ndikuwagwiritsa ntchito ngati feteleza pakukula kwa mbewu.
Chifukwa chake, kuphunzira za nitrogen fixation nthawi zonse kwakhala mutu wofunikira wofufuza zasayansi. Chifukwa chake, ndikofunikira kuti timvetsetse mawonekedwe olumikizirana ndi kapangidwe ka valence bond ya nayitrogeni mwatsatanetsatane.
Mtundu wa bond
Mapangidwe a ma elekitironi a valence a atomu ya N ndi 2s2p3, ndiko kuti, pali ma elekitironi atatu amodzi ndi ma electron awiriawiri. Kutengera izi, popanga zophatikiza, mitundu itatu yotsatirayi imatha kupangidwa:
1. Kupanga ma ionic bond 2. Kupanga ma covalent bond 3. Kupanga ma coordination bond
1. Kupanga ma ionic zomangira
Ma atomu a N ali ndi mphamvu yayikulu yamagetsi (3.04). Akapanga nitrides bayinare ndi zitsulo ndi electronegativity m'munsi, monga Li (electronegativity 0.98), Ca (electronegativity 1.00), ndi Mg (electronegativity 1.31), akhoza kupeza 3 ma elekitironi ndi kupanga N3- ayoni. N2+ 6 Li == 2 Li3N N2+ 3 Ca == Ca3N2 N2+ 3 Mg =ignite= Mg3N2 N3- ions ali ndi mtengo woipa kwambiri komanso utali wokulirapo (171pm). Adzakhala ndi hydrolyzed kwambiri akakumana ndi mamolekyu amadzi. Choncho, mankhwala a ionic amatha kukhalapo pakauma, ndipo sipadzakhala ma hydrated ions a N3-.
2. Kupanga ma covalent bond
Pamene ma atomu a N apanga zinthu zopanda zitsulo zokhala ndi ma electronegativity apamwamba, ma covalent bond awa amapangidwa:
⑴N maatomu amatenga sp3 hybridization state, kupanga ma covalent bond atatu, kusunga ma electron awiriawiri, ndipo masinthidwe a molecular ndi trigonal pyramidal, monga NH3, NF3, NCl3, ndi zina zotero. tetrahedron wokhazikika, monga ma NH4+ ayoni.
⑵N maatomu amatenga sp2 hybridization state, kupanga ma bond awiri ogwirizana ndi chomangira chimodzi, ndikusunga ma electron awiriawiri, ndipo masinthidwe a molekyulu amakhala aang'ono, monga Cl—N=O. (N atomu imapanga mgwirizano wa σ ndi mgwirizano wa π ndi Cl atomu, ndipo awiriawiri awiri a electron pa atomu ya N amapangitsa molekyulu kukhala katatu.) NO3-yoni. Mu molekyulu ya nitric acid, N atomu imapanga zomangira zitatu za σ ndi ma atomu atatu O motsatana, ndipo ma elekitironi awiri pa π orbital yake ndi ma elekitironi amodzi a ma O atomu awiri amapanga chomangira chapakati chapakati cha ma elekitironi anayi delocalized π. Mu nitrate ion, 4-center six-electron delocalized lalikulu π chomangira chimapangidwa pakati pa ma atomu atatu O ndi chapakati N atomu. Kapangidwe kameneka kamapangitsa nambala yowoneka bwino ya okosijeni ya N atomu mu nitric acid +5. Chifukwa cha kukhalapo kwa ma bond akuluakulu a π, nitrate imakhala yokhazikika pamikhalidwe yabwinobwino. ⑶N atomu imatengera kusakanizidwa kwa sp kupanga mgwirizano wolumikizana katatu ndikusunga ma electron awiriawiri. Kusintha kwa mamolekyulu ndikofanana, monga kapangidwe ka atomu ya N2 mu molekyulu ya N2 ndi CN-.
3. Kupanga ma coordination bonds
Ma atomu a nayitrogeni akapanga zinthu zosavuta kapena zophatikiza, nthawi zambiri zimasunga ma electron awiriawiri, kotero kuti zinthu zosavuta zotere zimatha kukhala ngati ma electron awiri opereka kuti agwirizane ndi ayoni achitsulo. Mwachitsanzo, [Cu(NH3)4]2+ kapena [Tu(NH2)5]7, ndi zina zotero.
Chithunzi cha oxidation state-Gibbs free energy
Zitha kuwonedwanso kuchokera ku mawonekedwe a oxidation state-Gibbs free energy chithunzi cha nayitrogeni kuti, kupatula ma NH4 ayoni, molekyulu ya N2 yokhala ndi nambala ya okosijeni ya 0 ili pamunsi kwambiri pamapindikira pazithunzi, zomwe zikuwonetsa kuti N2 ndi thermodynamically. okhazikika poyerekezera ndi mankhwala a nayitrogeni okhala ndi ziwerengero zina za okosijeni.
Miyezo yamitundu yosiyanasiyana ya nayitrogeni yokhala ndi manambala a oxidation pakati pa 0 ndi +5 onse ali pamwamba pa mzere wolumikiza mfundo ziwiri za HNO3 ndi N2 (mzere wa madontho pazithunzi), kotero kuti mankhwalawa ndi osakhazikika komanso osakhazikika. Chokhacho chomwe chili pazithunzi chokhala ndi mtengo wotsika kuposa molekyulu ya N2 ndi NH4 + ion. [1] Kuchokera pa chithunzi cha oxidation state-Gibbs mphamvu yaulere ya nayitrogeni ndi kapangidwe ka molekyulu ya N2, zitha kuwoneka kuti elemental N2 siyikugwira ntchito. Pokhapokha pa kutentha kwakukulu, kuthamanga kwambiri komanso kukhalapo kwa chothandizira kuti nayitrojeni igwirizane ndi haidrojeni kuti ipange ammonia: Mumikhalidwe yotayira, nayitrogeni imatha kuphatikiza ndi okosijeni kupanga nitric oxide: N2 + O2 = discharge = 2NO Nitric oxide imaphatikizana mwachangu ndi okosijeni. kupanga nitrogen dioxide 2NO+O2=2NO2 Nitrogen dioxide amasungunuka m'madzi kupanga nitric acid, nitric oxide 3NO2+H2O=2HNO3+NO M'mayiko omwe ali ndi mphamvu zopangira mphamvu zamadzi, izi zakhala zikugwiritsidwa ntchito popanga nitric acid. N2 imakhudzidwa ndi haidrojeni kuti ipange ammonia: N2+3H2=== (chizindikiro chosinthika) 2NH3 N2 imachita ndi zitsulo zokhala ndi mphamvu yotsika ya ionization ndipo ma nitridi ake amakhala ndi mphamvu ya lattice yayikulu kupanga ma ionic nitrides. Mwachitsanzo: N2 akhoza kuchita mwachindunji ndi zitsulo lithiamu kutentha firiji: 6 Li + N2 === 2 Li3N N2 amachitira ndi zamchere lapansi zitsulo Mg, Ca, Sr, Ba pa kutentha incandescent: 3 Ca + N2 === Ca3N2 N2 akhoza zimangochita ndi boron ndi aluminiyamu pa kutentha kwa incandescent: 2 B + N2 === 2 BN (macromolecule pawiri) N2 nthawi zambiri imachita ndi silicon ndi zinthu zina zamagulu pa kutentha kwakukulu kuposa 1473K.
Molekyu ya nayitrogeni imathandizira ma electron atatu kuti agwirizane, ndiye kuti, kupanga ma bond awiri a π ndi amodzi σ. Sichimathandizira kuti pakhale mgwirizano, ndipo mphamvu zomangira ndi zotsutsana ndi zotsutsana ndizochepa, ndipo zimakhala zofanana ndi ma electron awiriawiri. Chifukwa pali chomangira chapatatu N≡N mu molekyulu ya N2, molekyulu ya N2 imakhala yokhazikika, ndipo zimatengera 941.69kJ / mol mphamvu kuti iwononge kukhala maatomu. Molekyu ya N2 ndiyokhazikika kwambiri mwa mamolekyu odziwika bwino a diatomic, ndipo ma molekyulu a nayitrogeni ndi 28. Komanso, nayitrogeni siwosavuta kuwotcha ndipo sichirikiza kuyaka.
Nthawi yotumiza: Jul-23-2024
