252 Table 262. 



COMPOSITION AND ELECTROMOTIVE FORCE OF VOLTAIC CELLS. 



The electromotive forces given in this table approximately represent what may be expected from a cell in good work- 

 ing order, but with the exception of the standard cells all of them are subject to considerable variatiou. 



(a) Double Fluid Cells. 



Name of 

 cell. 



Negative pole. 



Solution. 



Positive 

 pole. 



Solution. 





Bunsen . 



Chromate 



Daniell* 



Grove 



Amalgamated zinc 



Marie Davy 

 Partz . . 



I part H2SO4 to ) 

 12 parts H2O . ) 



[12 parts KaCrsOT] 

 I to 25 parts of I 

 j H.2SO4 and 100 [ 

 [ parts H2O . . J 



I part H2SO4 to I 

 12 parts H2O . ) 



I part H2SO4 to I 

 4 parts H2O . ) 



I part H2SO4 to 

 12 parts H2O . 



5% solution of 

 ZnS04 + 6H2O 



I part NaCl to 

 4 parts H2O . 



I part H2SO4 to 

 12 parts H2O . 



Solution of ZnS04 



H2SO4 solution, ) 

 density 1.136 . ) 



( H2SO4 solution, I 

 ( density 1.136 .J 



{H2SO4 solution, 1 

 density 1.06 . ) 



( H2SO4 solution, ) 

 ( density 1.14 . ) 



H2SO4 solution, 

 density 1.06 . 



NaCI solution . . 



( I part H2SO4 to ) 

 I 12 parts H2O ) 



Solution of MgS04 



Carbon 



Fuming H2NO3 

 HNO3, density 1.38 



( I part H2SO4 to ) 

 I 12 parts H2O . 5 



Copper 



12 parts K2Cr207 ( 

 to 100 parts HoO J 



Saturated solution ) 

 ofCuS04+5H20 j 



Platinum 



Carbon 



Fuming HNO3 . . 

 HNO3, density 1.33 

 Concentrated HNO3 



PINO3, density 1.33 



HNO3, density 1.19 



" density 1.33 



! Paste of protosul- ) 

 phate of mercury > 

 and water . . . ) 



Solution of K2Cr207 



1.94 

 1.86 



2.00 



2.03 



.06 



.09 



.08 



•05 



•93 

 .66 



•93 



•79 



•71 



.66 



.61 

 .88 



.50 



2.06 



* The Minotto or Sawdust, the Meidinger, the Callaud, and the Lockwood cells are modifications of the Daniell, 

 and hence have about the same electromotive force. 



Smithsonian Tables. 



