182 



S. E. Moody — Hydrolysis of Salts. 



an equal volume of water and 3 grms. of ammonium sulphate 

 were added, and a current of one ampere was found sufficient 

 to deposit the nickel upon a rotating platinum crucible in thirty 

 minutes. 



Below is shown results of these determinations. 



N1SO4 (NH 4 ) 2 S0 4 



25 

 25 

 25 

 25 

 25 



grm. 

 3 

 3 

 3 

 3 

 3 



Time 



in 



minutes. 



30 

 30 

 30 

 30 

 30 



Table IX. 



Ni = 



grm. 

 0-0520 

 0-0523 

 0-0521 

 0-0523 

 0-0522 



S0 3 = 



grm. 

 0-0709 

 0-0713 

 0-0711 

 0*0713 

 0-0712 



I. 



Mean of 

 entire 



series. 

 grm. 



grm. 

 0-2246 ) 

 0-2260 I 

 0-2252 y 0-2255 

 0-2260 J 



0-2255 J 



A portion of 25 cm3 of the solution of nickelous sulphate was 

 drawn from a burette into a Yoit flask and a solution of 1 gm. 

 of potassium iodide in 15 cm3 of the potassium iodate (30 grms. 

 to a liter) was added. This was heated for three hours in the 

 presence of hydrogen to aid in the transfer of the iodine liber- 

 ated to the receiver — a Drexel flask about half full of water in 

 which 3 grms. of potassium iodide is dissolved. The iodine 

 liberated was estimated with sodium thiosulphate in the presence 

 of starch. 



Results of these determinations follow. 











Table X. 





Iodine 













Approx. 



I. 



value 





^iS0 4 . 



KI. 



K1O3 



Time 



N/10 



calcu- 



of Ni. 



Diff. 









in 



Na 2 S 2 3 . 



lated. 



table. 





cm 3 . 



grm. 



cm 3 . 



hours. 



cm 3 . 



grm. 



grm. 



grm. 



25 



1-0 



15 



3 



17-87 



0*2254 



0-2255 



—o-oooi 



25 



1-0 



15 



3 



17-88 



0-2256 



0-2255 



+ 0-0001 



25 



1-0 



15 



3 



17-84 



0-2250 



0-2255 



— 0-0005 



25 



1-0 



15 



3 



17-87 



0-2254 



0-2255 



—o-oooi 



35 



ro 



15 



3 



17-83 



0-2249 



0-2255 



— 0-0006 



Thus it appears that nickel sulphate may be completely 

 hydrolyzed in the presence of the iodide-iodate mixture and 

 that the nickel of nickel sulphate of ideal composition can be 

 estimated from the amount of iodine liberated in the action of 

 that salt upon the iodide-iodate mixture. 



Zinc. 

 Zinc sulphate is hydrolyzed in the presence of the iodide- 

 iodate mixture and the reaction might be expected to proceed 

 according to the following equation : 



3ZnS0 4 + 5KI + KI0 3 = 3Zn(OH) 2 + 3K 2 S 4 + 6l 

 For the purpose of experimenting upon this salt, a solution 



