



S. E. Moody — Hydrolysis of Salts 



181 









Table VII. 







CoS0 4 . 



(NH 4 ) 2 S04 Time in 

 minutes. 



.Co = S0 3 = 



= I. 



Mean of 

 entire series 



cm 3 . 

 25 



grms 

 3 



30 



grm. grm. 

 0-0528 0-0710 



grm. 

 0-2250 "i 



grm. 



25 



3 



30 



0-0525 0-0706 



0-2237 





25 

 25 



3 

 3 



30 

 30 



0*0524 0-0705 

 0-0527 0-0709 



0-2234 

 0-2247 



0-2242 



25 



3 



30 



0^0526 0-0707 



0-2240 





25 



3 



30 



0-0527 0-0709 



0-2247 





Subjecting portions of cobaltous sulphate to heat with potas- 

 sium iodide and potassium iodate in the presence of a current 

 of hydrogen to transfer the iodine to a Drexel flask charged 

 with potassium iodide, the following results were obtained : 











Table VIII. 



Iodine 



Iodine 













Approx. 



value 



value 





S04. 



EX 



KIO3. 



Time 



N/10 



calcu- 



of C0SO4 



Diff. 









in 



Na 2 S 2 3 . 



lated. 



taken. 





mr 3 . 



grm. 



cm 3 . 



hours. 



cm 3 . 



grm. 



grm. 



grm. 



25 



1-0 



15 



4 



17-80 



0-2244 



0*2242 



+ 0-0002 



25 



1-0 



15 



3* 



"17-78 



0-2242 



0-2242 



±0-0000 



25 



1-0 



15 



3* 



17-75 



0-2238 



0-2242 



— 0-0004 



25 



1-0 



15 



4 



17-79 



0-2243 



0-2242 



+ 0-0001 



25 



1-0 



15 



4 



17-79 



02243 



0-2242 



+ 0-0001 



25 



1-0 



15 



4 



17-78 



0-2242 



0-2242 



±0-0000 



It should be observed that the iodine value obtained by the 

 action of the iodide-iodate mixture upon the samples of cobal- 

 tous sulphate examined is closely comparable with the iodine 

 equivalent of the cobalt found by the electrolytic deposition 

 of the metal, showing that it is an exact measure of the cobalt 

 present in the completely hydrolyzed cobaltous sulphate of 

 ideal composition. 



Nickel. 



Xickelous sulphate, like cobaltous sulphate, is hydrolyzed 

 completely, after a considerable time, in the presence of the 

 iodide-iodate mixture, likewise yielding iodine, which may be 

 collected similarly and estimated as a measure of the nickel 

 present. Xickelous hydroxide formed in the reaction remains, 

 however, unoxidized by potassium iodate in neutral solution 

 and therefore the following equation will show the final pro- 

 ducts : 



3NiS0 4 + 5KI + KI0 3 + 3H 2 = 3Ni(OH) 2 + 3 K 2 S0 4 + 6l 



The standard of the solution examined was obtained by the 

 electrolytic process. To 25 cm 3 in a beaker of convenient size 



