Observations on the rare earths : yttrium chloride and the atomic weight of yttrium . the lower numbers being the grams per fraction. From these results it may be concluded that the method serves very wellwhen fairly pure yttria is used as a starting material. Small quantities ofErbium are easily removed and also some very pure yttria may be separated froma mixture containing holmium. However, the method does not give good resultsfrom mixtures containing earths of the oerium group. The method used in the determination of the atomic weights was the con-version of weighed quantities of oxide to
Observations on the rare earths : yttrium chloride and the atomic weight of yttrium . the lower numbers being the grams per fraction. From these results it may be concluded that the method serves very wellwhen fairly pure yttria is used as a starting material. Small quantities ofErbium are easily removed and also some very pure yttria may be separated froma mixture containing holmium. However, the method does not give good resultsfrom mixtures containing earths of the oerium group. The method used in the determination of the atomic weights was the con-version of weighed quantities of oxide to anhydrous sulphate. Since yttriumhas no visible absorption spectra the atomic weights were depended on to showboth the course of the fractionation and the purity of the material in thefinal fraotions. However, there seemed to be considerable uncertainty aboutthe results by this method for if not heated enough to thoroughly dehydrateand remove the excess aoid the results would be low, and if heated too mucha basio sulphate was formed and the results would be high. So it was evident. -12-th at by varying the heating process of the sulphate almost any atomio weightvalue within oertain limits could be obtained. Even where run in pairs, eaohsample undergoing identically the same treatments, good checks were not alwayssecured. Since it \vas evident that no exaot knoiTledge of the purity of the oxideoould be obtained by this method the further fractionation of the materialwas considered impractioal until a reliable method was found for the determi-nation of the atomio weights. Three lines of prooedure suggested themselves. 1st. To study conditions and endeavor to obtain more consistent results from the Y-^03 : Y2(S04)3 ratio, and to oompare it with other methods. 2nd. To prepare anhydrous yttrium 28 ) ohloride and find the ratio YCI3 : 3Ag, as Baxter and Chapin have alreadydone for neodymium, and, 3rd, to determine the ratio Yz03 : 2YCI3. With thispurpose in view the fraotions contain
Size: 1346px × 1857px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjecttheses, bookyear1912
