POTENTIOMETRIC AND SPECTROPHOTOMETRIC STUDY OF THE ACID-BASE EQUILIBRIA OF CR(VI) AT 25-DEGREES-C AND DIFFERENT IONIC STRENGTHS OF AQUEOUS KNO3

被引：10

作者：

OLAZABAL, MA

BORGE, G

CASTANO, R

ETXEBARRIA, N

MADARIAGA, JM

机构：

[1] Kimika Analitikoaren Departamentua, Euskal Herriko Unibertsitatea, Bilbao, E-48080

来源：

JOURNAL OF SOLUTION CHEMISTRY | 1993年 / 22卷 / 09期

关键词：

CR(VI); ACID-BASE EQUILIBRIA; SPECTROPHOTOMETRIC PROPERTIES; VARIABLE IONIC STRENGTH; POTENTIOMETRIC TITRATION;

D O I：

10.1007/BF00648585

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The hydrolysis of the chromate ion has been studied using a potentiometric-spectrophotometric automated titration system, titrating basic K2CrO4-KNO3 solutions with previously standarized HNO3-KNO3 solutions. The temperature was kept constant at 25-degrees-C and the ionic strengths were 0.5, 1.0 and 2.0 mol-dm-3. The resulting titration curves can be interpreted in terms of two equilibria involving the formation of HCrO4-(aq) and Cr2O72-(aq). A spectrophotometric batch study was also carried out in order to obtain the thermodynamic constant for the HCrO4-(aq) formation as well as the spectrophotometric parameters at low ionic strengths. The proposed stoichiometric constants for the two reactions and the molar absorptivities for the three species at different wavelengths and ionic strengths are also given.

引用

页码：825 / 838

页数：14

共 20 条

[1] ABSORPTION OF CARBON DIOXIDE BY SOLUTIONS OF 2-AMINO-2-(HYDROXYMETHYL)-1,3-PROPANEDIOL [J].