Gooch and Kuzirian — Use of Sodium, Paratung state. 499 



The strontium carbonate used in the experiments given 

 below was prepared with great care. Strontium chloride, 

 C. P., was partially precipitated by strong hydrochloric acid, 

 washed with hydrochloric acid, dissolved in water and added 

 in dilute solution drop by drop from a stoppered funnel to a 

 saturated solution of ammonium carbonate heated to the point 

 of decomposition. The precipitated carbonate was carefully 

 washed, dried, washed again with ammonium carbonate and 

 then with boiling water, and dried below red heat. In Table 

 II are the results obtained with this preparation of strontium 

 carbonate. 



Table II. 



Analysis of Specially Precipitated Strontium Carbonate. 



SrC0 3 

 taken 

 grru. 



0-5000 

 0-5000 

 0-5000 

 0-5000 

 0-5000 

 0-5000 



Na 10 Wi 2 O 4 i 



taken 



(approx.) 



grin. 



2-5 

 2-5 

 2-5 

 2-5 

 2-5 

 2-5 



Loss on 



ignition 



grm. 



0-1488 

 0-1494 

 0-1494 

 0-1490 

 0-1496 

 0-1486 



Theory for 

 C0 2 

 grm. 



0-1490 

 0-1490 

 0-1490 

 0-1490 

 0-1490 

 0-1490 



Error 

 grm. 



— 0-0002 

 + 0-0004 

 + 0-0004 



0-0000 

 + 0-0006 



— 0-0004 



With barium carbouate prepared from the chloride by par- 

 tial precipitation with strong hydrochloric acid, solution of 

 the precipitated chloride in water, gradual addition of the 

 solution with constant stirring to a hot solution of ammonium 

 carbonate, careful washing, and drying, the following results 

 were obtained : 







Table 



III 







Analysis of Specially Precipitated Barium 



Carbonates. 



BaC0 3 



taken 



taken 

 (approx.) 



Loss on 

 ignition 





Theory for 



Error 



grm. 



grm. 



grm. 





grm. 



grm. 



0-5000 



2-5 



0-1120 





0-1115 



+ 0-0005 



0-5000 



2-5 



0-1125 





0-1115 



+ 0-0010 



0-5000 



2-5 



0-1109 





0-1115 



— 0-0004 



0-5000 



2-5 



0-1113 





0-1115 



— 0-0002 



0-5000 



2-5 



0-1123 





0-1115 



— 0-0008 



The similar use of sodium paratungstate for the determina- 

 tion of the nitrogen pentoxide in nitrates is shown in the 

 following; table : 



