384 



Gooch and Blake — The Perchlorate Method 



Table II contains results of experiments with potassium 

 chloride. Those of section A represent results obtained by 

 keeping the washing liquid within moderate limits. In section 

 B are the results obtained by using the first filtrate instead 

 of the washing liquid to effect the transfer of the precip- 

 itate to the filter. 



The results and details of similar experiments with pure 

 rubidium and caesium chlorides are given in Tables III and lY 

 and with mixtures of potassium, rubidium, and csesium chlo- 

 rides in Table Y. 



Table III. 

 The Determiyiation of Rubidium as the Perchlorate. 



RbCl 

 taken 

 grm. 



RbC104 Theory 

 found for 

 grm. RbC104 

 grm. 



Error 

 grm. 



HCIO4 Filtrate 

 (70^) (Approx.) 

 cm^ cm^ 



The transfer made with the washing solution after 

 digesting fifteen to twenty minutes. 



•1000 



0- 



•1000 



0- 



•1000 



0^ 



•1000 



0- 



•1000 



0- 



•1000 



0- 



•1000 



0' 



•1000 



0- 



1527 0-1529 — 0-0002 0^1 60 



1528 0-1529 —0-0001 0-1 60 



1529 0-1529 —0-0000 01 60 



1527 0-1529 -0-0002 0-1 20-f20 



1531 0-1529 +0-0002 O'l 20 + 20 



1531 0-1529 +0-0002 5 60 



1530 0-1529 +0-0001 5 60 

 1526 0-1529 —0.0003 5 60 



iOne evaporation 

 in glass. 



) One evaporation ; two 

 t decantations. 



One evaporation 

 in glass. 



B 



The transfer made with the washing liquid without 

 standing to digest. 



0-1000 



0-1526 



0-1529 



-0-0003* 



5 



60 



0-1000 



0-1525 



0-1529 



— 0-0004* 



5 



60 



01000 



0-1524 



0-1529 



— 0-0005* 



5 



60 



0-1000 



0-1521 



0.1529 



— 0-0008* 



5 



60 



0-1000 



0-1508 



0-1529 



-0-0021* 



5 



60 



1 



I One evaporation with 

 y large amount of 

 I perchloric acid. 



J 



The transfer effected, after digestion, with the use of the filtrate. 



0-1000 0-1534 0-1529 +0 0004 3X0-1 20 + 5 

 0-1000 0-1526 0-1529 —0 0003 3X0-1 20 + 5 



Three evaporations 

 in platinum. 



* These results are low in spite of possible contamination by silica. 

 Table V, A. 



See 



