Organik moddalar tarkibidagi galogenlarni aniqlash
REAKTIV VA METERIALLAR: dixloretan (xloroform), etil spirti, natriy metali, 10% li nitrat kislota, distillangan suv, 5% li kumush nitrat, mis sim, 1 m li xlorid kislota.
a) beylshteyn usuli. uzunligi 10-12 sm bo’lgan mis simning uchini spiral qilib, gaz alangasida rangi doimiy qizg’ish bo’lguncha qizdiriladi. sim sovutilganda uning yuzasi oksidlanib qorayadi. simning spiral uchini tekshirilayotgan moddaga botirib olib, alangaga tutiladi. alanga tiniq yashil rangga bo’yaladi, bunda quyidagicha reaksiya boradi:
2CHCl3 5CuO 2CO2 H2O 4CuCl CuCl2
b) stepanov usuli. bu usulga ko’ra galloidni aniqlash uchun modda tarkibidagi galogenni ion holiga o’tkazish kerak, chunki organik birikmalarning kovalent bog’li galogen birikmalari dissotsillanmaydi.
probirkaga 3 tomchi xloroform va 3 tomchi etil spirti solib aralashtiring, kattaligi moshdek keladigan natriy metalini unga tushiring, probirkada shiddatli reaksiya boshlanadi, aralashma loyqalanadi, chunki spirtda yomon eriydigan osh tuzi hosil bo’ladi. natriy to’la reaksiyaga kirishib bo’lgach, probirkadagi aralashmaga 5-6 tomchi distillangan suv qo’shiladi. aralashma kislotali muhitga ega bo’lishi uchun unga 2-3 tomchi 10% li nitrat kislota tomizing, so’ngra 2-3 tomchi 5% li kumush nitrat qo’shiladi. natijada kumush xlorid pag’a-pag’a oq cho’kmaga tushadi:
2C2H5OH 2Na 2C2H5ONa H2 CHCl3 6H CH4 3HCl C2H5ONa HCl C2H5oH NaCl NaCl AgNO3 AgCl NaNO3
тekshirilayotgan modda tarkibida yod bo’lsa, cho’kma sariq, brom bo’lsa och sariq rangga bo’yaladi.
analiz qilinayotgan birikma sifatida dixloretan, dibrommetan olinganda qanday reaksiyalar borishini yozing.
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