Coulometric Bromometric Titration of Free and Coordinately Linked Cyanides
نویسندگان
چکیده
The conditions of coulom9tric bromometric determination of cyanides in weak alkaline medium of the borate buffer solution are described. I t is possible to titrate free cyanides and the cyanides linked coordinately in Cr(CN*)jp and Cr(CN)6N0 ~. The equivalence point of titration is indicated biamperometrically. The presence of air oxygen influences the results of free cyanide determination. The reaction scheme is discussed on the basis of different results obtained in bromometric oxidation of cyanides and cyanide complexes. The determinations were performed in the concentration range from 94.8 to 2020 (xg of KCN*. The accuracy of determination corresponding to 95% probability is expressed for 2020, 776, and 94.8 (jLg of KCN by the reliability interval of i 10.1, ± 7.5, and ± 1.3 \ig of KCN, respectively. The coulometric bromometric titration of cyanide is especially suitable for the determination of cyanides in the presence of chlorides and bromides. Chlorides do not interfere even if the ratio СГ/CN" has the value of 2.7 X 10. Bromides do not interfere provided that the ratio Br~/CN~ does not exceed the value of 5.9 X 10.
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تاریخ انتشار 2013