Electroanalytical investigations on formation of thallium(I) molybdates as a function of pH

• Main Authors: Prasad Shiva, Brito André L.F., Leite Valderí D., Souza Antônio G.
• Format: Article
• Language: English
• Published: Sociedade Brasileira de Química 2002-01-01
• Series: Journal of the Brazilian Chemical Society
• Subjects: molybdates; thallium(I) molybdates; electrometry
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532002000400013

The formation of thallium(I) molybdates obtained by interaction of thallium(I) nitrate and sodium molybdate at specific pH levels 7.6, 5.5 and 4.1 has been studied by electrometric techniques involving potentiometric and conductometric titrations, in aqueous and alcoholic media using each reagent as titrant. Well defined breaks and inflections in the titration curves provide cogent evidence for formation of thallium normal-Tl2O.MoO3, para-3Tl2O.7MoO3 and octa-2Tl2O.8MoO3 molybdates in the vicinity of pH 6.8, 5.9 and 5.2, respectively. Analytical investigations of the precipitates of thallium(I) molybdates have also been carried out, which substantiate the results of the electrometric study.