ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Salts of periodic acid. X. Lead periodates

M. Drátovský and J. Matějčková

Lehrstuhl für anorganische Chemie der Naturwissenschaftlichen Fakultät an der Karls-Universität, Praha

Abstract:   By the method of the gradual pptn. (Souchay and Hessaby, CA 47, 11870d), the existence of the known Pb₃(IO₅)2.H₂O with Pb:I of 3:2 was proven. Willard and Thompson described Pb3(IO5)2 as a dihydrate (CA 28, 63808) but refused to accept other periodates with Pb:I of 1:1 and 2:1, described by Giollitti (Gazz. Chim. Ital. 32, 345(1902)). By the study of the equil. of the heterogeneous systems Pb₃(IO₅)2.H₂O-H₅IO₆-H₂O and Pb₃(IO₅)₂.-H₂O-KOH-H₂O, Pb₂I₂O₉.3H₂O with Pb:I of 1:1 and Pb₄I₂O₁₁.5H₂O with Pb:I of 2:1 were detd. The conditions for the prepn. of these two compds. were different from those described by Giollitti. In the heterogeneous reaction of the liquid HIO₅ and solid Pb₃(IO₅)₂.H2O, the equil. is reached at ∼20° and the Pb:I of 1:1 salt was formed if the amt. of HIO₅ was between 15 to 40%. In strongly alk. media with KOH concns. between 5.4 to 20%, the Pb:I of 2:1 salt was formed. From the pH-titrn. measurements (Nasanen, CA 49, 7430i) of the system NaIO₄-Pb(NO₃)₂-H₂O, the soly. product of Pb₃(IO₅)₂.H₂O was calcd. From the analysis of the solid phase liberated during the titrn., the formation at pH 2.1-3.0 of Pb₃(IO₅)₂.H₂O and at pH 7.4-8.6, Pb₄I₂O₁₁.5H₂O was detd. The soly. product of Pb₃(IO₅)₂.H₂O was calcd. for 7 values of pH at 2.1 to 3.0. The av. value of the neg. log of the soly. product was 19.9 ± 0.3.

Full paper in Portable Document Format: 196a447.pdf (in Czech)

Chemical Papers 19 (6) 447–455 (1965)