HYDROO 





will serve as a good conductor, with another el 

 trodes being also connected bj wires with electrical a] 

 measuring the total potential of the battery; then by addJ 

 to or subtracting this value from the total potential 

 sign of the unknown electrode we can tell the potential 

 electrode. 



We have discussed these principles of electrochemisti 

 form the basis upon which depends the Btandard method the deter- 



mination of the H-ion concentration of fluids. Suppose 

 thai in place of using a metal in the construction <>: 

 use an electrode consisting <>t' a layer of pure hydro 

 with a solution in which are free II ions: then the rate ;it whiel II 



fi'.S^ 



J pf^-l 3-"V -- ,f 



+ © + 



-Diagram ol foi thi 



rent k<"|" ' ated in the batten 

 lion, and the II ele< trode) or ■ ■ 



:-i the bi idffe w ire, w >" i e i h< 

 liri.l«<- win- from an accumulat 

 nt at various : 



S"i' n~i ill 



become added to the solution from the II !.v , .ik- , n from 



• 



pend on the concentration of II ions in Bolution. I 



hydrogen electrode fulfilling the abo 



employ some means by which a layer "t" hydrogen may !•• 



fortunately this can be done by taking advanta 



Bpongy platinum possesses of absorbing larg It 



is also necessary to keep an atmosphi H 



fluid. 



As is tli.' case «'t" the simpler cells 

 types \\lii<-li we mighl use for measurii 

 erated in tin* unknov n • - 1 * • « ■ t rode n • 



