Published 1982 | Version v1
Journal article Metadata-only

Arsenates of rare-metals: electrometric investigations on praseodymium arsenates as a function of pH

Creators

  • 1. Paraiba Univ., Joao Pessoa (Brazil). Dept. de Engenharia Quimica

Description

The stoichiometry of the compounds formed by the interaction of praseodymium chloride and different alkali arsenates (meta, pyro and ortho) at specific pH levels - 7.2, 8.3 and 11.1 - were investigated by electrometric techniques involving pH measurements and potentiometric and condutometric titrations. The inflections and breaks in the tiration curves provide evidence for the formation of three praseodymium arsenates having the moleuclar formulae Pr2O3.3 As2O5 ,2Pr2O3.3As2O5 and Pr2O3.As2O5 in the vicinity of pH 4.8, 5.8 and 7.0, respectively. Analysis of the compounds by conventional methods (gravimetric, as oxide, for praseodymium; iodometric for arsenic) substantiate the results of the electrometric study. (Author)

Abstract (Portuguese)

Investigou-se a estequiometria de compostos formados pela interacao do cloreto de praseodimio com diferentes arsenatos alcalinos (meta, piro e orto) em pH's 7,2 , 8,3 e 11,1 , por tecnicas eletrometricas envolvendo medidas de pH e titulacoes potenciometricas e condutometricas. As inflexoes das curvas de titulacao fornecem evidencia da formacao de tres arsenatos de praseodimio com formulas moleculares : Pr2O3.3As2O5 , 2 Pr2O3.3As2O5 e Pr2O3.As2O5 na vizinhanca de pH 4.8 , 5,8 e 7,0 , respectivamente. As analises dos compostos por metodos convencionais (gravimetria para o Pr como oxido e iodometria para o arsenio) apresentaram resultados concordantes com os do estudo eletrometrico. (Autor)

Additional details

Additional titles

Original title (Portuguese)
Arseniatos de metais-raros: investigacoes eletrometricas sobre arseniatos de praseodimio como funcao do pH

Publishing Information

Journal Title
An. Assoc. Bras. Quim.
Journal Volume
33
Journal Issue
1-4
Series
An. Assoc. Bras. Quim.
Journal Page Range
85-88
ISSN
0365-0073

INIS

Country of Publication
Brazil
Country of Input or Organization
Brazil
INIS RN
16052801
Subject category
S37: INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; S37: INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY;
Descriptors DEI
ARSENATES; COMPARATIVE EVALUATIONS; ELECTRIC CONDUCTIVITY; GRAVIMETRIC ANALYSIS; IODOMETRY; PH VALUE; POTENTIOMETRY; PRASEODYMIUM
Descriptors DEC
ARSENIC COMPOUNDS; CHEMICAL ANALYSIS; DESTRUCTIVE ANALYSIS; ELECTRICAL PROPERTIES; ELEMENTS; METALS; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; QUANTITATIVE CHEMICAL ANALYSIS; RARE EARTHS; TITRATION