Table 383 {continued). 2 J^ 3 



COMPOSITION AND ELECTROMOTIVE FORCE OF VOLTAIC CELLS. 



Name of cell. 



Negative 

 pole. 



Solution. 



Positive pole. 



E. M. F. 



in volts. 



(b) Single Fluid Cells. 



I>eclanche . . . 



Chaperon . . . 

 Edison-Lelande . 

 Chloride of silver 

 Law 



Dry cell (Gassner) 

 Poggendorff . . 



J. Regnault . . 

 Volta couple , 



Amal. zinc 



Zinc 



Amal. zinc i 



Solution of sal-ammo- 

 niac 



Solution of caustic 

 potash .... 



Zinc 



23 % solution of sal- \ 

 ammoniac . . . . f 



ipl.^ZnO, ipLNHiCl,] 



3 pts. plaster of paris, 1 



2 pts. ZnCl2,and water [ 



to make a paste . . J 



Solution of chromate ) 



of potash . . . . j 



12 parts K2Cr207 -f ) 



25 parts H2SO4 -j- ( 



. 100 parts U2O . . ) 



I part H2SO4 + j 



12 parts H2O -f V 



I part CaSOi . . ) 



HoO 



(Carbon. Depolari- 

 zer : manganese 

 peroxide with 

 powdered carbon J 

 j Copper. Depolar- \ 

 I izer ; CuO . . . j 



Silver. Depolari 

 zer: silver chl'ride 

 Carbon . 



Cadmium 

 Copper . 



1.46 



0.98 

 0.70 

 1.02 



1-3 



1.08 

 2.01 



0.34 

 0.98 



(c) Standard Cells. 



Weston normal 



Clark standard 



iCadmi'm/ 

 ( am'lgamj 



Zinc i 

 am'lgam ! 



Saturated solution of 

 CdS04 



Saturated solution of 

 ZnSU4 



{Mercury. 

 Depolarizer: paste 

 of Hg2S04 and 

 CdS04 . . . . 



{Mercury. 

 Depolarizer; paste 

 of Hg2S04 and 

 ZnS04 . . . . 



1. 01 83* 

 at 20° C 



I -434 

 at i5°C 



(d) Secovdarv Cells. 



Lead accumulator 



Regnier (i) . . . 

 (2). . . 



Main . 

 Edison 



Lead 



Copper . 



Amal. zinc 

 Amal. zinc 



Iron . . 



H2SO4 solution of J 

 density i.i . . . j 



CUSO4 -f H2SO4 . . 



ZnS04 solution . , . 

 H2SO4 density ab't i.i 



KOH 20 % solution . 



PbOa 



" in H2SO4 

 A nickel oxide 



* The temperature formula is Ej =: Ejo — 0.0000406 (t — 20) — 0.00000095 (t — 20)* -|- o.oooooooi (t — ao)'. 

 \ The value given for the Clark cell is the old one adopted by the Chicago International Electrical Congress in 1893- 

 The temperature formula is Ej=: E15 — 0.00119 (' — '5) — 0.000007 (t — 15)2. 



dE 

 t F. Strejntz gives the following value of the temperature variation — at different stages of charge : 



dt 

 E. M. F. 1.9223 1.QS28 2.0031 2.0084 2.0105 2.0779 2.2070 



dE/dtXio« 140 228 335 285 255 130 73 



Dolezalek gives the following relation between E. M. F and acid concentration : 

 Per cent H0SO4 64.5 52.2 35.3 21.4 5.2 

 E.M.F., o°C 2.37 2.25 2.10 2.00 1,89 



Smithsonian Tables. 



