25- lab mashg’uloti. 12-guruh elementlari. Rux, kadmiy va simob birikmalari. Laboratoriya ishining maqsadi

Alyuminiy, galliy, indiy birikmalari, xossalari
8-tajriba. Alyuminiy gidroksidning amfoterligi.
Probirkaga 8-10 tomchi alyuminiyning eriydigan tuz eritmasidan solib, unga suyultirilgan o‘yuvchi natriy eritmasidan oq iviq cho‘kma tushguncha tomchilatib qo‘shing. Probirkani chayqatib ko‘ring. Cho‘kma erimasligi shart. Reaksiya tenglamasini molekulyar va ionli shaklda yozing. Hosil bo‘lgan cho‘kmani ikkita probirkaga bo‘ling. Birinchisiga suyultirilgan HCl yoki H 2SO 4 dan, ikkinchisiga esa o‘yuvchi natriy eritmasidan cho‘kmalar erib ketguncha qo‘shing. Reaksiya tenglamalarini molekulyar va ionli shaklda yozing.
9-tajriba. Alyuminiy tuzlarining gidrolizi
a) alyuminiy nitrat va alyuminiy sulfat tuzlari eritmasini qizil va ko‘k lakmus qog‘ozlari bilan sinab ko‘ring. Kuzatilgan hodisaga qarab, shu tuzlarning bosqichli gidroliz reaksiyalari tenglamalarini molekulyar va ionli shaklda yozing;
___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ b) probirkaga alyuminiy sulfat eritmasidan 8-10 tomchi solib, unga shuncha hajmda natriy atsetat eritmasidan qo‘shing. Eritmalarni qo‘shgandan cho‘kma hosil bo‘lmaydi. Aralashma qaynatilganda esa alyuminiyning asosli tuzi (Al(OH)₂CH₃COO)
cho‘kmaga tushishini kuzating. Reaksiya tenglamasini yozing;
_____________________________________________________________________________________________________________________________________________________________________________________________________________________ d) probirkaga 5-6 tomchi alyuminiy sulfat eritmasidan solib, ustiga shuncha hajmda soda eritmasidan tomizing. Oq iviq cho‘kma hosil bo‘lib, gaz ajralib chiqishini kuzating.
Gidroliz tenglamasini yozing. Gidrolizning oxirgi bosqichigacha to‘liq borishini tushuntiring;
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e) probirkaga 4-5 tomchi alyuminiy sulfat eritmasidan solib, unga bir necha tomchi 2 n o‘yuvchi natriy eritmasidan (cho‘kma hosil bo‘lib, to‘liq erib ketguncha) qo‘shing. Hosil
bo‘lgan natriy tetragidroksodiakvoalyuminat eritmasiga 5-6 tomchi suv va bir necha dona ammoniy xlorid kristallaridan aralashtiring. Aralashmani qaynaguncha qizdiring. Cho‘kma hosil bo‘lishini va gaz ajralib chiqishini (hididan bilasiz) kuzating. Reaksiya tenglamalarini yozing.
_____________________________________________________________________________________________________________________________________________________________________________________________________________________Xulosa.______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

28- lab.mashg’uloti. 14 guruh elementlarii.Uglerod birikmalari va xossalari.