112 



Gooch and Burdich — Electro- Analysis. 



Electrolysis zcith Rotating Cathode: cell, disc, cathode, 

 and reverse filter, weighed together. 



Determination of Copper. 









Initial 







Metal 



Metal 





current 







taken 



taken 



Error 



, » v 



Approx. 



Time 



grm. 



grm. 



grm. 



amp. 



volt. 



N.D.,oo 



min. 



0-1272 



0-1273 



o-oooi 



1 



5 



50 



20 



0-1272 



0-1276 



0-0004 



1 



5 



50 



20 



0-1272 



0-1272 



0-0004 



1-2 



5 



60 



20 



0-1272 



0-1-274 



o-oooo 



1-2 



5 



60 



20 





Determination 



of Nickel. 













Initial 







Metal 



Metal 





current 







taken 



taken 



Error 



, 



* — ( 



Approx. 



Time 



grm. 



grm. 



grm. 



amp. 



volt. 



N.D.,00 



min. 



0-0743 



0-0743 



0-0000 



0-6 



6 



30 



30 



0-0743 



0-0744 



+ 0-0001 



0-8 



8 



40 



30 



0-0748 



0-0744 



— 0-0004 



1 



10 



50 



30 



0-0743 



0-0738 



— 0-0005 



1 



7 



50 



30 



0-0743 



0-0741 



— 0-0002 



1 



7 



50 



30 



Electrolysis of Copper Sulphate loithout rotation of the 

 cathode : cell, disc, and filter weighed together. 



Copper 

 taken 

 grm. 



0-1272 

 0-1272 

 0-1272 

 0-1272 



Copper 

 taken 

 grm. 



0-1282 

 0-1282 

 0-1276 

 0-1275 



Error 

 grm. 



+ 0-0010 

 + 0-0010 

 + 0-0004 

 + 0-0003 



Initial 

 current 



amp. 



1-2 

 1-1 

 2 

 2 



volt. 



6 

 5 

 5 

 5 



Approx. 

 N.D.,00 



60 



60 

 100 

 100 



Time 

 min. 



35 

 30 

 30 

 30 



It is obvious that the process without rotation is inferior in 

 point of accuracy to the otherwise similar process in which 

 the cathode is rotated. 



The construction of the apparatus is very simple and the use 

 very easy. The weight of stand, cell, cathode, and filter tube 

 together need not exceed 17 gms. to 18 gms. ; and that of the 

 platinum used need not be more than 1 grm. 



The results are best and most rapidly obtained when the 

 cathode is rotated, but this device may be relied upon to yield 

 reasonably accurate determinations when a rotating motor is 

 not available. 



