Noorganik kimyo kafedrasi analitik kimyo laboratoriya ishlanmalar

Fotometrik titrlash egri chizig'i

Titrlash egri chizig'idagi gorizontal kesma (eritmaning optik zichligi doimiy) barcha misning EDTA bilan kompleksga bog'lanishiga mos keladi. Egri chiziqdagi uzilish ekvivalentlik nuqtasiga to'g'ri keladi.

Kerakli jihozlar: 1) fotometrik titrator TFL-46-2, 2) 100 sm3 va 25 sm3 uchun byuretkalar; 3) 50 sm3 o'lchamli silindr; 4) 100 sm3 hajmli stakan.
Reaktivlar: 1) 0,05 N. ikki almashtirilgan natriy etilendiamintetraatsetatning standart eritmasi (Na2H2EDTA); 2) asetat bufer eritmasi (500 sm3 distillangan suv uchun 73,4 sm3 1 n sirka kislotasi va 50 sm3 1 n natriy gidroksid eritmasi ishlatiladi; pH = 5); 3) 0,02 n. mis (II) sulfatning standart eritmasi.

Old panelning joylashuvi fotometrik titrator TFL-46-2

Ishning borishi. Qurilmani o'zgartirish tugmasi 1 bilan yoqing. Qizil yorug'lik filtri № 8ni o'rnatish uchun titrator korpusining o'ng tomonidagi devordagi barabanni 11 aylantiring. ishlashi, valfni o'zgartirish tugmasi 2, sezgirlikning qo'pol va silliq o'zgarishi uchun tutqichlar 4 va 5 , shuningdek titrlash turini tanlash tugmasi 8 tegmang.

Qurilmaning kyuvetasiga 70 sm3 suv quyib, uni kyuveta blokiga 12. Oʻzgartirish tugmasi 7 boʻlgan aralashtirgichni yoqing va uning aylanish chastotasini 6-tugmacha bilan rostlang, shunda juda chuqur voronka kyuvetkadan oʻtayotgan yorugʻlik oqimini buzmaydi. yechim. Galvanometr ko'rsatkichini 9 ni 0 ni nol o'rnatish tugmasi bilan 3 ga qo'ying. Keyin suvni to'kib tashlang va byuretkadan 10 sm 3 mis tuzi eritmasini bir xil kyuvetaga o'lchang. Buning uchun 10-15 sm3 asetat buferi va 50-60 sm3 distillangan suv qo'shing. Kyuvetani titratorning 12-blokiga o'rnating, unga magnit elementni tushiring va aralashtirgichni yana yoqing.
Barabanning dastagini 10 aylantirib, og‘ishgan galvanometr ignasini 0 ga keltiring va uning shkalasiga dastlabki ko‘rsatkichni yozing. Kyuvetkadagi eritma byuretkadan 0,5 sm3 EDTA eritmasidan qo`shib titrlanadi. Har bir titrant qo'shilgandan so'ng, barabanni 10 aylantirib, galvanometr ko'rsatkichini 9 dan 0 ga qaytaring va baraban 10 shkalasida kuzatilgan qiymatlarni yozib oling. Bu doimiy qiymatlarga erishilgunga qadar amalga oshiriladi, shundan so'ng yana kamida 3 ball olinadi.
Olingan ma'lumotlar jadvalga kiritiladi, ular ustida grafik tuziladi va ekvivalentlik nuqtasi topiladi. Shundan so'ng, laboratoriya muhandisidan nazorat topshirig'i olinadi va bir xil operatsiyalar ketma-ketligi bilan titrlanadi. Titrlash egri chizig'idagi ekvivalent nuqtagacha bo'lgan titrant hajmi masaladagi mis miqdorini aniqlaydi.

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