Accession Number : AD0495805

Title :   Electrometric Titrations of Zirconium and Hafnium Solutions,

Corporate Author : WISCONSIN UNIV-MADISON DEPT OF CHEMISTRY

Personal Author(s) : Larsen, Edwin M. ; Gammill, Adrian M.

Report Date : 31 JAN 1950

Pagination or Media Count : 16

Abstract : The pH of precipitation of hafnium hydroxide is always higher than for zirconium hydroxide for the perchlorate, nitrate and chloride solutions at equivalent concentrations. The difference in the pH of precipitation for zirconium and hafnium from perchlorate solutions is very small, but the difference is quite marked in the nitrate and chloride solutions. The zirconium precipitates at progressively lower ratios of hydroxyl ion added to the metal ion concentration as the metal ion concentration is reduced, whereas the hafnium precipitates at nearly constant ratios. Increased anion concentration increases the pH of precipitation in all cases. For the sulfate solutions, the hafnium precipitates at lower pH's than the zirconium. The precipitates were probably basic sulfates. For the perchlorate solutions, over three-fourths of the precipitation range, the logarithm of the hydroxyl ion concentration is a linear function of the metal ion concentration. Solubility products for zirconium and hafnium hydroxides are calculated.

Descriptors :   *HAFNIUM COMPOUNDS), (*ZIRCONIUM COMPOUNDS, (*SOLUTIONS(MIXTURES), CHEMICAL PRECIPITATION), SOLUBILITY, CONCENTRATION(CHEMISTRY), VOLUMETRIC ANALYSIS, HYDROXIDES, IONS, PH FACTOR, SALTS, SULFATES, CHLORIDES, NITRATES, PERCHLORATES, COAGULATION.

Subject Categories : Inorganic Chemistry
      Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE