New spectrophotometric evidence for the existence of HCrO4-

被引：41

作者：

Cruywagen, JJ ^{[1
]}

Heyns, JBB ^{[1
]}

Rohwer, EA ^{[1
]}

机构：

[1] Univ Stellenbosch, Dept Chem, ZA-7600 Stellenbosch, South Africa

来源：

POLYHEDRON | 1998年 / 17卷 / 10期

关键词：

isosbestic point; chromate solution; spectrophotometry;

D O I：

10.1016/S0277-5387(97)00443-9

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

A spectrophotometric study of the protonation and dimerization of CrO42- at different concentrations in the pH range 8-2.5 at 25 degrees C in 0.1 M (Na)Cl medium led to the characterization of HCrO4- and Cr2O72-, in terms of formation constants and absorption spectra. When the pH is varied at constant Cr(VI) concentration the experimental spectra exhibit one real and three accidental isosbestic points. The results of this investigation do not corroborate recent work in which the non-existence of HCrO4- was claimed. The spectrophotometric determined equilibrium constants have been verified-by potentiometric titrations. The values are: log beta(11) = 6.09+/-0.04 and log beta(22) = 13.94+/-0.06. (C) 1998 Elsevier Science Ltd. All rights reserved.

引用

页码：1741 / 1746

页数：6

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