314 THE ATOMIC WEIGHTS. 



Seubert and Kobbe * determine the atomic weight by igniting rhodium 

 pentamine chloride in hydrogen, and weighing the residual metal. Their 

 results are given below : 



3 . Rh. Per cent. Rh. 



1.8585 .6496 34-953 



I -556o .5435 34.929 



1.5202 .5310 34-93 



2. 01 1 1 .7031 34.961 



1.8674 .6528 34.958 



2-4347 .8513 34-965 



2.3849 .8338 34.962 



2.5393 .8881 34-974 



1.4080 .4920 34-943 



1.4654 .5123 34.960 



Mean, 34-954, -0032 



In the sixth experiment the ammonium chloride formed was collected 

 in a bulb tube, and estimated by weighing as silver chloride. 3.5531 

 grms. of AgCl were obtained. 



Computing with N =13.935, .0021 ; Cl =35.179, -0048, and AgCl = 

 142.287, .0037, we have 



From per cent, of metal ............ Rh = 102.215, .0143 



From AgCl ratio ................ " = 102.287, =b .0324 



General mean Rh = 102.227, .0131 



If = 16, Rh = 103.006. 



In the second of these values the probable error given is only that due 

 to the antecedent atomic weights of N, Cl, and AgCl. It is therefore 

 lower than it should be. The two values, however, are fairly in agree- 

 ment, and the result is satisfactory. 



* Ann. d. Chem., 260, 318. 1890. 



