Nitric acid

Strong monobasic acid, wanda shi ne a misali yanayi colorless ruwa wanda ya jũya rawaya a lokacin ajiya iya zama a wani m jihar, halin da biyu crystalline gyare-gyare (monoclinic ko orthorhombic raga) a yanayin zafi a kasa debe 41,6 ° C. Wannan abu da sinadaran dabara - HNO3 - nitric acid da aka kira. Yana yana da wani matauni taro 63,0 g / mole, yayin da ta yawa yayi dace da 1,51 g / cm³. acid reflux zazzabi ya 82.6 ° C, yana tare da bazuwar daga cikin (m): 4HNO3 → 2H2O + 4NO2 + O2. acid bayani tare da wani taro sulusi da murabba'i na asali abu na 68% tafasa a zazzabi na 121 ° C. A Refractive index of tsarkakakke abu yayi dace 1.397. Acid za a iya gauraye da ruwa a wani rabo kuma, kasancewa mai karfi electrolyte, kusan gaba daya rarrabu cikin ions H + kuma NO3-. M tsari - trihydrate da monohydrate da ciwon da dabara: HNO3 • 3H2O da HNO3 • H2O bi da bi.

Nitric acid - lalata aiki, mai guba abu, da kuma mai karfi da oxidizing wakili. Daga tsakiyar zamanai aka sani da wannan sunan ba, kamar yadda "karfi ruwa» (Ruwa fortis). Alchemists wanda ya gano acid a cikin 13th karni, ya ba da sunan don tabbatar da shi m Properties (corroded duk karafa fãce zinariya), mafificin miliyan sau ikon acetic acid, wanda a kwanakin nan aka dauke da mafi yawan aiki. Amma ko da bayan karnuka uku an gano cewa, corrode, ko da zinariya iya zama wata cakuda acid kamar nitric da hydrochloric a juz'i na rabo na 1: 3, wanda wannan dalilin kira "Ruwa regia". Bayyanar wani rawaya launi a lokacin ajiya ne saboda da jari na nitrogen oxides a cikinsa. Samuwa acid tare da wani taro mafi sau da yawa 68%, da kuma lokacin da abun ciki na da tushe abu a kan 89% shi ne ake kira "fuming".

A sunadarai Properties na nitric acid, rarrabe shi daga tsarma sulfuric ko hydrochloric acid cewa HNO3 karfi oxidant haka ba saki hydrogen a halayen da karafa. Saboda da oxidative Properties, shi ma reacts da yawa wadanda ba karafa. Kuma a lokuta biyu ne ko da yaushe kafa nitrogen dioxide NO2. A redox halayen, a nitrogen dawo da faruwa zuwa sãɓãwar launukansa digiri: HNO3, NO2, N2O3, NO, N2O, N2, NH3, wanda aka ƙaddara da acid taro da kuma ayyuka na karfe. Kwayoyin na mahadi kafa ƙunshi nitrogen a hadawan abu da iskar shaka jihar +5, +4, +3, +2, +1, 0, +3, bi da bi. Alal misali, jan aka oxidized tare da mayar da hankali acid don jan nitrate (II): Cu + 4HNO3 → 2NO2 + Cu (NO3) 2 + 2H2O, kuma phosphorus - to metaphosphoric acid: P + 5HNO3 → 5NO2 + HPO3 + 2H2O.

In ba haka ba interacts da tsarma nitric acid nonmetals. A misali na dauki tare da phosphorus: 3P + 5HNO3 + 2H2O → 3H3PO4 + 5NO gani cewa nitrogen an rage zuwa divalent jihar. A sakamakon haka ne nitric oxide da phosphorus da aka oxidized zuwa acid phosphate. Dabzar nitric acid a admixture da hydrochloric acid dissolves zinariya: Au + 4HCl + HNO3 → NO + H [AuCl4] + 2H2O da platinum: 3Pt + 18HCl + 4HNO3 → 4NO + 3H2 [PtCl6] + 8H2O. A cikin wadannan halayen, da farko, hydrochloric acid da aka oxidized tare da nitric chlorine saki, sa'an nan ta samar da hadaddun karfe chlorides.

Nitric acid da aka samar kudi samu a uku main hanyoyi:

1. Origin - maida martani da salts da sulfuric acid: H2SO4 + NaNO3 → HNO3 + NaHSO4. A baya can, shi ne kaɗai hanya zuwa, amma tare da zuwan da sauran kimiyoyi, shi ne a halin yanzu yi amfani da dakin gwaje-gwaje don samar da fuming acid.
2. Na biyu - da shi ne a hanyar da na baka. Lokacin iska a kan wani lantarki baka da zazzabi na 3000 zuwa 3500 ° C, wani ɓangare na nitrogen a cikin iska reacts tare da oxygen, forming nitrogen monoxide: N2 + O2 → 2NO, wanda bayan sanyaya aka oxidized zuwa nitrogen dioxide (ba amsa a wata high zazzabi monoxide tare da oxygen) : O2 + 2NO → 2NO2. Sa'an nan, kusan, dukan nitrogen dioxide, a wani wuce haddi na oxygen, da narkar da a ruwa: 2H2O + 4NO2 + O2 → 4HNO3.
3. Na uku - wannan shi ne wani ammonia Hanyar. Ammonia ne oxidized a kan platinum mai kara kuzari ga nitrogen monoxide: 4NH3 + 5O2 → 4NO + 6H2O. A sakamakon nitrous gas an sanyaya, da kuma kafa nitrogen dioxide, wanda ake tunawa da ruwa. Ta wannan hanya, da acid da ciwon taro na 60 zuwa 62%.

Nitric acid da aka yi amfani da ko'ina a masana'antu don samar da kwayoyi, dyes, nakiyoyi, nitric takin zamani da nitric acid salts. Bugu da kari, shi da ake amfani da rushe karafa (msl, jan, gubar, da azurfa) cewa ba amsa tare da sauran acid. A amfani da kayan ado domin tabbatar da dalilin da zinariya a cikin gami (wannan shi ne babban Hanyar).