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8319289 
Journal Article 
Further investigation concerning the atomic weights of silver, lithium and chlorine 
Richards, TW; Willard, HH 
1910 
Yes 
Journal of the American Chemical Society
ISSN: 0002-7863
EISSN: 1520-5126 
32 
1 
4-49 
English 
This investigation consisted in a careful study of three ratios, namely that of lithium chloride to silver chloride, that of lithium chloride to silver, and that of lithium chloride to lithium perchlorate. By means of the last two ratios, 04 : Ag was calculated, and new values were obtained in this entirely new way for the atomic weights of silver, lithium and chlorine. In the process of this work new methods of purifying lithium salts, better than any preceding, were devised. Lithium chloride was fused in such a way as to show perfect neutrality to the most sensitive indicators, and was weighed in a strictly anhydrous condition. The preparation of perchloric acid also was subjected to rigid scrutiny, and this substance was made in a state of unusual purity. The sharpness of the end-point in the method used for determining the relation between silver and chlorine was much increased by cooling the solution to o°, in order to diminish the solubility of silver chloride. In other respects the methods of analysis developed in previous Harvard investigations were used in the determination of chlorine. A new precise method was devised for converting lithium chloride into lithium perchlorate, and its sources of error were carefully examined. 45.56877 grams of lithium chloride were found in seven experiments to yield 154.0602 grams of silver chloride on complete precipitation; and in another series of seven experiments partly independent from these 46.63197 grams of lithium chloride were found to need 118.65894 grams of silver for complete precipitation. In yet another series of six experiments, entirely independent, but using a similar preparation of lithium chloride, 34.40566 grams of this substance were converted into 86.34716 grams of lithium perchlorate. As an outcome of all these experiments, the atomic weight of lithium was found to be 6.939, and the atomic weight of silver 107,871, if oxygen is taken as 16.000. © 1910, American Chemical Society. All rights reserved.