The Transference Number of Hydrogen

Douglas. McIntosh
1898 The Journal of Physical Chemistry  
Transference iiuinhei-s :ire usuall>. deteriiiiiied accordiiig to the iiiethod of Hittorf' by electrolyzing a soliitioii and iiieasuriiig tlie chaiige of coiiceiitratioii at tlie aiiode or cathode. ' I' 1ii.q iiiethod is applicable iii all cases ; but the experimental errors are large. T h e iiietliod of Helmholtz is iiot applicable i n all cases ; h i t seeiiis to ha\-e verj-distinct adyaiitages wherever it can be used. IYlieii two cells of tlie type % n %iiSO,Hg,SO, ~ Hg are connected,
more » ... e connected, mercury to inercur!-, tlie effect of their action is to 1)riiig the two ziiic sulfate solutions to tlie saiiie coiiceiitratioii. Hehi~lioltz' lias slion-11 that the electroiiioti1.e force of such a concentration cell without diffusion ' caii be expressed iii teriil.. of t h e concentrations of the cells, together with tlie relation obtaining betweeii coiiceiitratioii aiid vapor pressure ; lie lias sli(jn.n, further, that tlie electroiiioti\-e forces of the allied coiiceiitr-'I t' 1011 cells with cliff usioii ' can be coiiiputed froiii the m i l e quantities. together with tlie tmiisfereiice iimiliel-of tlie anion of tlie t1i.;-.sol\.etl electroll-te : aiid, fiiiallj-, tliat tlie ratio of these t\i-o electroiiiotive forces, at a n y same teinperatui-e, is this transferenctx iiuiiiber. Let 9 tleiiote tlie free energ!. of a soliltion coiitaiiiiiig m , inas-iuiits of water aiicl iii2 of salt: and let the relati\-e ilia+ i n , , / i i 2 = /L of the water be knon-ii as the cliliitio:i-~-nlue of the solutioii. \Ye seek the rate of chaiige. n-it11 cliaiigiiig coiiceiitm-His reasoiiiiig is esseiitinl1:as follon-s :
doi:10.1021/j150005a001 fatcat:edr6brcgd5gjzcf7rbtyaytn4e