Amphoteric oxides. Chemical Properties, wani tsari domin shirya

Amphoteric oxides (da ciwon dual Properties) - a mafi yawan lokuta karfe oxides wanda da low electronegativity. Dangane da waje yanayi nuna wani acidic oxide ko Properties. Wadannan oxides an kafa ta mika mulki karafa, wanda yawanci nuna da wadannan hadawan abu da iskar shaka jihohi: ll, lll, LV.

Misalan amphoteric oxides: tutiya oxide (ZnO), chromium oxide lll (Cr2O3), aluminum oxide (Al2O3), oxide ll tin (SnO), tin oxide LV (SnO2), gubar oxide ll (PbO), gubar oxide LV (PbO2) , titanium oxide LV (TiO2), manganese oxide LV (MnO2), da baƙin ƙarfe oxide lll (Fe2O3), beryllium oxide (BeO).

A halayen hali na amphoteric oxides:

1. Wadannan oxides iya amsa tare da karfi acid. A wannan nau'i na salts daga cikin wadannan guda acid. Halayen da irin wannan wata alama ce ta kadarori na asali type. Ga misali: ZnO (tutiya oxide) + H2SO4 (hydrochloric acid) → ZnSO4 (tutiya sulfate) + H2O (ruwa).

2. A dauki da karfi alkalis amphoteric oxides, hydroxides nuna acidic Properties. A wannan biyuntakar na Properties (Ina nufin, amphoteric) shi ne bayyana a cikin samuwar biyu salts.

A narke ta dauki tare da Alkali gishiri da aka kafa da talakawan al'ada, misali:
ZnO (tutiya oxide) + 2NaOH (sodium hydroxide) → Na2ZnO2 (al'ada nufin gishiri) + H2O (ruwa).
Al2O3 (alumina) + 2NaOH (sodium hydroxide) = 2NaAlO2 + H2O (ruwa).
2Al (OH) 3 (aluminum hydroxide) + 3SO3 (sulfur oxide) = Al2 (SO4) 3 (aluminum sulfate) + 3H2O (ruwa).

The bayani amphoteric oxides ta dauki tare da Alkali ta samar da hadaddun gishiri, misali: Al2O3 (alumina) + 2NaOH (sodium hydroxide) + 3H2O (ruwa) + 2Na (Al (OH) 4) (a hadaddun gishiri na sodium tetragidroksoalyuminat).

3. Kowane wani amphoteric karfe oxide yana da wani daidaituwa lambar. Alal misali ga tutiya (Zn) - 4, aluminum (Al) - 4 ko 6, domin chromium (Kr) - 4 (m) ko 6.

4. Amphoteric oxide ba amsa tare da ruwa da kuma ba ya narke a cikinta.

Abin da halayen tabbatar amphoteric karfe?

In mun gwada magana, wani amphoteric kashi iya nuna da kaddarorin biyu karafa da kuma nonmetals. Irin wannan halayyar alama ne ba a cikin abubuwa na A kungiyoyin: Be (beryllium), Ga (gallium), Far (germanium), SN (tin), Pb, SB (antimony), Bi (bismuth), da kuma wasu daga cikinsu, kamar yadda da dama daga cikin abubuwa B -groups - a Kr (chromium), mn (manganese), Fe (iron), Zn (tutiya), CD (cadmium), da sauransu.

Mu yanzu tabbatar da wadannan sinadaran halayen amphoteric sinadari tutiya (Zn):

1. Zn (OH) 2 (tutiya hydroxide) + N2O5 (dinitrogen pentoxide) = Zn (NO3) 2 (tutiya nitrate) + H2O (ruwa).
ZnO (tutiya oxide) + 2HNO3 (nitric acid) = Zn (NO3) 2 (tutiya nitrate) + H2O (ruwa).

b) Zn (OH) 2 (tutiya hydroxide) + Na2O (sodium oxide) = Na2ZnO2 (sodium dioksotsinkat) + H2O (ruwa).
ZnO (tutiya oxide) + 2NaOH (sodium hydroxide) = Na2ZnO2 (sodium dioksotsinkat) + H2O (ruwa).

A wannan yanayin, idan kashi tare da dual Properties na fili yana da wadannan hadawan abu da iskar shaka, ta dual (amphoteric) Properties mafi kula faruwa a wani tsaka-tsaki hadawan abu da iskar shaka mataki.

Kamar yadda misali za a iya Chrome (Kr). Wannan kashi yana da wadannan hadawan abu da iskar shaka jihohi: 3+, 2+ 6+. A cikin hali na uku na asali da kuma acidic Properties aka bayyana kamar daidai, yayin da y Kr +2 asali Properties fi, kuma a Kr +6 - acid. A nan ne halayen da tabbatar da wannan bayani:

Kr + 2 → cro (chromium oxide +2), Kr (OH) 2 → CrSO4.
Kr + 3 → Cr2O3 (chromium oxide +3), Kr (OH) 3 (chromium hydroxide) → KCrO2 ko chromium sulphate Cr2 (SO4) 3.
Kr + 6 → CrO3 (chromium oxide +6), H2CrO4 → K2CrO4.

A mafi yawan lokuta amphoteric oxides da sunadarai abubuwa a hadawan abu da iskar shaka jihar +3 zama a cikin meta form. Kamar yadda misali za a iya kawo sunayensu: Aluminum hydroxide oxide (sinadaran da dabara Alo (OH) da na baƙin ƙarfe metahydroxide (sinadaran FeO (OH) dabara) ...

Ta yaya ne amphoteric oxides?

1. The mafi m hanya domin su shiri ne hazo daga wani ruwa-ruwa bayani amfani ammonium hydroxide, cewa shi ne mai rauni tushe. Ga misali:
Al (NO3) 3 (aluminum nitrate) + 3 (H2OxNH3) (ruwa-ruwa bayani daga ammonia hydrate) = Al (OH) 3 (amphoteric oxide) + 3NH4NO3 (dauki aka yi a karkashin zafin rana ashirin digiri).
Al (NO3) 3 (aluminum nitrate) + 3 (H2OxNH3) (ruwa-ruwa ammonium hydroxide) = Alo (OH) (amphoteric oxide) + 3NH4NO3 + H2O (dauki yi a 80 ° C)

A musayar dauki na da irin wannan a cikin hali na wuce haddi Alkali aluminum hydroxide ba zai precipitate. Wannan shi ne saboda gaskiyar cewa aluminum wuce a cikin anion saboda ta dual Properties: Al (OH) 3 (aluminum hydroxide) + OH- (haddi Alkali) = [Al (OH) 4] - (aluminum hydroxide anion).

Misalai na irin wannan dauki:
Al (NO3) 3 (aluminum nitrate) + 4NaOH (haddi sodium hydroxide) = 3NaNO3 + Na (Al (OH) 4).
ZnSO4 (tutiya sulfate) + 4NaOH (haddi sodium hydroxide) = Na2SO4 + Na2 (Zn (OH) 4).

Salts wanda aka kafa a lokaci guda, suna hadaddun mahadi. Sun hada da hadaddun anions: (Al (OH) 4) - da kuma wani (Zn (OH) 4) 2-. Wannan shi ne saboda wadannan salts ake kira: Na (Al (OH) 4) - sodium tetragidroksoalyuminat, Na2 (Zn (OH) 4) - sodium tetragidroksotsinkat. Reaction kayayyakin da aluminum ko tutiya oxides tare da m Alkali ake kira daban: NaAlO2 - sodium dioksoalyuminat da Na2ZnO2 - sodium dioksotsinkat.