Mvura Yendarama
Mareagents anowanika nyore - chero munyu unonyungudika wemutobvu uye potassium iodide - inobvumira kuedza kunonakidza. Nekudaro, panguva yekuyedza, isu tinofanirwa kurangarira kungwarira zvakanyanya kana tichishanda neane muchetura makemiru. Panguva yebvunzo, hatidyi kana kunwa, uye tapedza basa, tinonyatsogeza maoko edu uye midziyo yegirazi yemurabhoritari. Mukuwedzera, aya ndiwo mazano echigarire kune testal chemist.
Ngatigadzirirei mareagents anotevera: munyu unonyungudika we lead (II) - nitrate (V) Pb (NO3)2 kana acetate (CH3Mukuru wekushanda)2Pb- uye potassium iodide KI. Isu tinogadzirira mhinduro kubva kwavari nehuwandu hunosvika 10%. Mushonga wemunyu unotungamira unodururwa muflask, uye ipapo vhoriyamu shoma yeKI mhinduro inowedzerwa. Mushure mekubvongodza mvura yakabva yagadzira yellow precipitate yemutobvu (II) iodide PbI.2 (mufananidzo 1):
Pb2+ + 2i- → PbI2↓
Dzivisa mushonga we potassium iodide yakawandisa, sezvo mvura inonyunguduka pahuwandu hweiyo iodide ions (complex compound K.2[PbI4]).
Iyo yero precipitate inonyanya kunyungudika mumvura inopisa. Mushure mekuisa furasiki mumudziyo mukuru wemvura inopisa (kana kuipisa pamusoro pemoto unopisa), mvura inonaya inopera nokukurumidza uye isina ruvara (mufananidzo 2) kana mushonga weyero zvishoma. Sezvo flask inotonhora, makristasi anotanga kuoneka muchimiro chegoridhe plaque (mufananidzo 3) Iyi ndiyo mhedzisiro yeinononoka crystallization ye lead(II) iodide inokonzerwa nekunyungudika kushoma kwemunyu mune inotonhorera. Apo patinokurudzira zviri mukati mefurasiki uye kuvhenekera mudziyo kubva parutivi, tichaona zita rokuti "golden shower" (tsvaga tsanangudzo yekuedza uku paInternet pasi pezita iri). Mhedzisiro yemuyedzo inofananawo nedutu rechando rechando rine zvisina kujairika - goridhe - petals (Mufananidzo 4 ne5).
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