Nititi ya asidi

Asidi amphamvu a monobasic, omwe ali ndi madzi opanda mtundu pansi pa zikhalidwe zoyenera, zomwe zimasanduka chikasu pamene zisungidwa, zikhoza kukhala zolimba, zomwe zimadziwika ndi makina awiri amodzi (monoclinic kapena rhombic lattice), kutentha pansi pa 41.6 ° C. Thupili ndi mankhwala amodzi - HNO3 - amatchedwa nitric acid. Ndili ndi masentimita 63.0 g / mol, ndipo mphamvu yake imakhala yofanana ndi 1.51 g / cm³. Malo otentha a asidi ndi 82.6 ° C, njirayi imatsatiridwa ndi kuwonongeka (tsankho): 4HNO3 → 2H2O + 4NO2 + O2. Njira yothetsera asidi ndi magawo ambiri a zinthu zomwe zimagwirizana ndi 68% zithupsa kutentha kwa 121 ° C. Mndandanda wa mankhwala oyeretsa umakhala ndi 1.397. Asidi amatha kusanganikirana ndi madzi mu chiŵerengero chilichonse ndipo, pokhala electrolyte wamphamvu, pafupifupi amatha kukhala H + ndi NO3-ions. Maonekedwe olimba - trihydrate ndi monohydrate ali ndi njira: HNO3 • 3H2O ndi HNO3 • H2O, motero.

Mankhwala a nitric ndi mankhwala owopsa, mankhwala owopsa ndi oxidizer amphamvu. Kuchokera ku Middle Ages, dzina "madzi amphamvu" (Aqua fortis) amadziwika. Akatswiri a zamagetsi, omwe anapeza asidi m'zaka za zana la 13, adatchula dzinali, atsimikiza kuti ali ndi zida zake zodabwitsa (zowonongeka zitsulo kupatulapo golidi), zopitirira mamiliyoni ambiri mphamvu ya asidi acid, yomwe m'masiku amenewo idawoneka ngati yogwira ntchito kwambiri. Koma patadutsa zaka mazana atatu, zinapezeka kuti mankhwala osakaniza monga nitric ndi hydrochloric acid mu chiwerengero cha 1: 3, chomwe chimatchedwa "royal vodka", chikhoza kusokonezedwa, ngakhale golidi. Kuwonekera kwa mthunzi wachikasu pa nthawi yosungirako kumafotokozedwa ndi kusungunuka kwa oksijeni oksijeni mmenemo. Pogulitsidwa, asidi nthawi zambiri amakhala pamtunda wa 68%, ndipo pamene zinthu zomwe zili ndizoposa 89% zimatchedwa "fuming".

Mankhwalawa a nitric acid amasiyanitsa ndi kuchepetsa sulfuric kapena hydrochloric acids kuti HNO3 ndi amphamvu oxidizer, kotero hydrogen si anatulutsidwa mu zochita ndi zitsulo. Chifukwa cha zowonongeka, zimayimbanso ndi ambiri osakhala ndi zitsulo. Pazochitika zonsezi, NO2 imapangidwa nthawi zonse. Zotsatira za redox, kuchepetsa nayitrogeni kumachitika madigiri osiyanasiyana: HNO3, NO2, N2O3, NO, N2O, N2, NH3, omwe amadziwika ndi ndondomeko ya asidi ndi ntchito zitsulo. Mamolekyu a mankhwalawa amapangidwa ndi nayitrogeni ndi dziko la okosijeni la +5, +4, +3, +2, +1, 0, +3, mofanana. Mwachitsanzo, mkuwa ndi okosijeni ndi ayitoni (II) nitrate: Cu + 4HNO3 → 2NO2 + Cu (NO3) 2 + 2H2O, ndi phosphorous kuti azikhala ndi phosphorous acid: P + 5HNO3 → 5NO2 + HPO3 + 2H2O.

Apo ayi, kuchepetsa asidi ya nitric kumayendetsedwa ndi osatembenuka. Pogwiritsa ntchito chitsanzo cha phosphorous: 3P + 5HNO3 + 2H2O → 3H3PO4 + 5NO, tingaone kuti nayitrojeni yafupika kuti isinthe. Chifukwa chake, nitrogen monoxide imapangidwa, ndipo phosphorous ili ndi oxidized ndi phosphoric acid. Mchere wa nitric wokhazikika pamodzi ndi hydrochloric acid umasungunula golide: Au + 4HCl + HNO3 → NO + H [AuCl4] + 2H2O ndi platinamu: 3Pt + 18HCl + 4HNO3 → 4NO + 3H2 [PtCl6] + 8H2O. Momwe amachitira zimenezi, panthawi yoyamba, hydrochloric acid ndi oxidized ndi nayitrogeni ndi chlorine imatulutsidwa, ndipo kenako zitsulo zimapanga zovuta mankhwala a chlorides.

Asidi a nitric pa mafakitale amapezeka m'njira zitatu izi:

1. Choyamba ndi kugwirizana kwa mchere ndi sulfuric acid: H2SO4 + NaNO3 → HNO3 + NaHSO4. Poyamba, njirayi inali imodzi yokha, koma, pakufika kwa matekinoloje ena, tsopano imagwiritsidwa ntchito mu labotale kuti ipange asidi a fuming.
2. Yachiwiri ndi njira ya arc. Pamene mpweya ukuwombera pamtunda wa magetsi ndi kutentha kwa 3000 mpaka 3500 ° C, nayitrogeni ya mlengalenga imayendetsedwa ndi mpweya, ndi kupanga nayitrogeni monoxide: N2 + O2 → 2NO, yomwe pambuyo pozizira imaphatikizidwa ndi nitrogen dioxide (pa kutentha, monoxide sichitengera mpweya) : O2 + 2NO → 2NO2. Ndiye, pafupifupi nitrogen dioxide, ndi oxygen yambiri, imasungunuka m'madzi: 2H2O + 4NO2 + O2 → 4HNO3.
3. Njira yachitatu ndi njira ya ammonia. Ammonia ndi oxidized pa chothandizira cha platinamu ku nitrojeni monoxide: 4NH3 + 5O2 → 4NO + 6H2O. Zopangidwa ndi nitroses zazirala, ndipo nayitrojeni ya dioxide imapangidwira, yomwe imagwedezeka ndi madzi. Njira imeneyi imapanga asidi ndi masentimita 60 mpaka 62%.

Asidi amchere m'makampani amagwiritsidwa ntchito kwambiri popanga mankhwala, madayira, mabomba, nitrogen feteleza ndi asidi a nitric acid. Komanso, amagwiritsidwa ntchito kuthetsa zitsulo (mwachitsanzo, mkuwa, kutsogolo, siliva) zomwe sizikugwirizana ndi zida zina. Mu bizinesi yamagetsi amagwiritsidwa ntchito kupeza golidi mu alloy (njira iyi ndi yaikulu).