262 Table 294. 



COMPOSITION AND ELECTROMOTIVE FORCE OF VOLTAIC CELLS. 



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

 ing order, but with the exception of the sundard cells aU of them are subject to considerable variation. 



Name of 

 cell. 



Bunsen 



Chromate 



Daniell* . 



Grove 



(a) Double Fluid Cblls. 



Negative pole. 



Amalgamated zinc 



Marie Davy 

 Partz . 



Solution. 



Positive 

 pole. 



( I part H2SO4 to 

 I 12 



parts H2O 



i2partsK.2Cr207 ^ 



to 25 parts of 1 



j H2SO4 and 100 I 



[ parts H2O . . J 



( I part H2SO4 to ) 

 \ 12 parts H2O . S 



I part H2SO4 to I 

 4 parts H2O . I 



I part H2SO4 to I 

 1 2 parts H2O . j 



5% solution of 1 

 ZnS04 + 6H2O ( 



( I part NaCl to 

 ( 4 parts H2O . 



j I part H0SO4 to I 

 I 12 parts H2O . ) 



Solution of ZnS04 



H2SO4 solution, 

 density 1.136 . 



H2SO4 solution, 

 density 1.136 . 



H2SO4 solution, 

 density 1.06 . 



( H2SO4 solution, ) 

 ( density 1.14 . | 



( H2SO4 solution, 

 ( density 1.06 . 



NaCl solution . . 



Carbon 



Copper 



Platinum 



Solution. 



Fuming H2NO3 

 HNO3, density 1.3S 



I part H2SO4 to 

 12 parts H2O . 



12 parts K2Cr207 |^ 

 to 100 parts H2O \ 



Saturated solution ) 

 ofCuS04+5H20) 



I part H0SO4 to } 

 12 parts H2O ) 



Solution of MgS04 



Carbon 



Fuming HNO3 . . 

 HNO3, density 1.33 

 Concentrated HNO3 



HNO3, density 1.33 



HNO3, density 1.19 



" density 1.33 



( Paste of protosul- ) 

 } phate of mercury > 

 ( and water . . . ) 



Solution of K2Cr207 



W.S 



1.94 



1.86 

 2.00 



2.03 

 1.06 

 1.09 

 1.08 

 1.05 



1-93 

 1.66 



1-93 



1.79 



1.71 



1.66 



1.61 



1. 88 



1.50 

 2.06 



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

 and hence have about the same electromotive force. 

 Smithsonian Tables. 



