i-volcano yamakhemikhali

Okunye okumangalisa kakhulu ukusabela kwamakhemikhali inqubo yokubola kwe-ammonium dichromate (VI) (NH4) 2Cr2O7, eyaziwa ngokuthi "i-volcano yamakhemikhali". Ngesikhathi sokusabela, kukhishwa inani elikhulu lezinto ezinama-porous, kulingisa udaka lwentaba-mlilo. Ezinsukwini zokuqala ze-cinema, ukubola kwe-(NH4)2Cr2O7 kwaze kwasetshenziswa "njengomphumela okhethekile"! Abahloli abafisa ukwenza ucwaningo bayacelwa ukuthi bangakwenzi ekhaya (ngenxa yokuphuma kothuli olundizayo olungangcolisa indlu).

Ukuze wenze ukuhlolwa, uzodinga i-porcelain crucible (noma omunye umkhumbi okwazi ukumelana nokushisa) ogcwele i-ammonium (VI) dichromate (NH₄)₂Cr₂O₇ (isithombe 1). Beka i-crucible phezu kwendunduma yesihlabathi ulingisa ikhoni yentaba-mlilo (Pic 2) bese ukhanyisa impushana ewolintshi ngomentshisi (Pic 3). Ngemva kwesikhathi esithile, inqubo esheshayo yokubola kwe-compound iqala, okuholela ekukhululweni kwenani elikhulu lemikhiqizo yegesi, ehlakaza i-porous chromium oxide (III) Cr.₂O₃ (Izithombe 4, 5 kanye 6). Ngemva kokuphela kokusabela, yonke into ezungezile imbozwe ngothuli oluluhlaza (isithombe 7).

Ukusabela kokubola okuqhubekayo kwe-ammonium dichromate (VI) kungabhalwa nge-equation:

Ukuguqulwa kuwukusabela kwe-redox (okuthiwa ukusabela kwe-redox), lapho isimo se-oxidation sama-athomu akhethiwe sishintsha. Kulokhu kusabela, i-oxidizing agent (into ezuza ama-electron futhi inciphise isimo sayo se-oxidation) yi-chromium (VI):

I-ejenti yokunciphisa (into enikela ngama-electron futhi, ngakho-ke, inyusa izinga le-oxidation) iyi-nitrogen equkethwe ku-ammonium ion (sicabangela ama-athomu amabili e-nitrogen ngenxa ye-N.₂):

Njengoba inani lama-electron anikelwe i-ejenti yokunciphisa kufanele lilingane nenani lama-electron amukelwa i-oxidizing agent, siphindaphinda isibalo sokuqala ngo-2 nhlangothi zombili futhi silinganisela inani lama-athomu omoya-mpilo kanye ne-hydrogen asele.