l62 RESEARCHES UPON ATOMIC WEIGHTS. 



The following vacuum corrections were applied: 



A No. 10 Troemner balance easily sensitive to 0.02 mg. was used in all the 

 weighings. The gold-plated weights were carefully standardized to hundredths 

 of a milHgram by the method described by Richards.^ 



Weighing was always carried out by substitution, with the use of a counter- 

 poise as nearly as possible Uiie the object weighed, both in material, shape 

 and volume. 



Series III. sAgBr: Ag2Cr207. 



Ag 



AgBr 



= 0.574453^ 



No. of 

 anal- 

 ysis. 



I 

 2 



3 

 4 

 5 

 6 



7 

 8 



9 



Sample 

 of 



Ag2Cr207 



II 



II 



II 



III 



III 



III 



I 



I 



III 



Corrected 

 weight of 

 AgzCrjOj. 



gm. 



5-71554 

 4.87301 



7-45476 

 4-75269 



8.15615 

 6.15412 

 6.83662 



5-39883 

 6.26657 



Total . . 55.60829 



Weight of 

 AgBr in 

 vacuum. 



gm. 

 4.97107 

 4.23870 

 6.48380 

 4.13409 

 7.09477 

 5-35306 

 5-94656 

 4.69610 

 4.16034^ 



Weight of 

 asbestos. 



gm. 



0.00024 

 0.00019 

 0.00034 

 0.00020 

 0.00022 

 0.00007 

 0.00030 

 0.00027 

 0.00018 



Dissolved 



AgBr from 



filtrate. 



gm. 



0.00025 

 0.00003 

 0.00019 

 0.00003 

 0.00005 

 0.00007 

 0.00009 

 0.00007 

 0.00040 



Loss on 

 fusion. 



gm. 

 0.00007 

 0.00004 

 0.00008 

 0.00012 

 0.00009 

 o. 0001 1 

 0.00017 

 0.00013 

 0.00016 



Corrected 



weight of 



AgBr in 



vacuum. 



gm. 

 4.97149 

 4.23888 

 6.48425 

 4.13420 

 7-09495 

 S-35309 

 5.94678 

 4.69631 

 4.16076^ 



Ratio 



2.\gBr: 



Ag2Cr207. 



0.869820 

 0.869S69 

 0.869813 

 0.869865 

 0.869890 

 0.869839 

 0.869842 

 0.869876 

 0.8699034 



Average 0.869857 



48.37126 0.869854 



Average from Sample I 0.869859 



Average from Sample II 0.869834 



Average from Sample III 0.869874 



Average 0.869856 



Per cent of Ag in Agv-CraO?, if 2 AgBr: Ag2Cr207 



= 0.869857:1.000000 49.9692 



1 Jour. Amer. Chem. Soc, 22, 144 (1900). 



* Baxter, Loc. cit. 

 » AgCl. 



* Calculated from the ratio AgBr: AgCl = 131.0171: 100.0000. 

 gm. AgCl =0=5.45131 gm. AgBr. 



Baxter, Loc. cit. 4.16076 



