372 Gooch and Kobayashi — Determination of Flu wine 



Table I. 

 Conditions Affecting the Precipitation of Thorium Fluoride. 



A. 



Effect of Varying Amounts of Thorium 



Nitrate. 





Weight of Th0 2 



Variation 









corresponding 



in amounts 



Weight of 





Total 



to fluoride taken of reagents 



ThO a found 



Error 



volume 



grm. 





grm. 



grm. 



cm 8 



00688 



Thorium nitrate 

 50% in excess 



00687 



—00001 



SO 



00688 



Thorium nitrate 

 100% in excess 



00646 



—00042 



90 



00688 



Thorium nitrate 

 200% in excess 



00462 



—00226 



100 



B. 



Effect of Varying Amounts of Nitric Acid and Sulphuric Acid: 

 Thorium Nitrate 50% in Excess. 



00679 



HN0 3 -cone 



. 002 cm 3 



00622 



—00057 



30 



00679 



n < t 



01 " 



00584 



—00095 



30 



00679 



< < a 



0-4 " 



00564 



—00115 



• 30 



00679 



H 2 S0 4 - " 



102 " 



00711 



+00032 



30 



00679 



< < a 



1-27 " 



00681 



+00002 



30 



00679 



a it 



1-52 " 



00639 



—00040 



30 



c. 



Effect of Varying Amounts of Acetic Acid: 

 Thorium Nitrate 50% in Excess. 



00679 Acetic acid: 001 N 00727 +00048 30 



0018 grm. 

 00679 Acetic acid: 002 N 00675 —00004 30 



0036 grm. 

 0-0679 Acetic acid: 006 N 00676 —00003 30 



0108 grm. 

 0-0679 Acetic acid: 013 N 00673 —00006 30 



0-234 grm. 

 00679 Acetic acid: 0-26 N 00664 —00005 30 



0-468 grm. 

 00679 Acetic acid: 2-75 N 00658 —00021 30 



4-95 grm. 



vent action upon the precipitate, while the action of sul- 

 phuric acid is considerable. On the other hand, the 

 action of acetic acid in properly regulated proportion is 

 not only permissible but necessary to secure a proper 

 acidity of the solution. From the figures given, it appears 

 that the amounts of acetic acid may vary between about 



