Question

How the concentration polarization occurs in galvanic and electrolylic cells

Answer 1

The consentoration, within the dillution layer changes chonges forom 6 (bulk concentration) to Cool contentration at electrode surface). Corresponding the electrode batential changes within the from diffusion layer - E. (RI loge C MF to Es Eo LRT MF loge Ç The difference between Es and Eb is called consentration overpatenttal, which is the measure of consentration polarization mc = Es-Eb RT G InF Сь = loge (a of electric The concentration over patential may be also expressed through the values current and limiting electric current passing through the diffusion layer, Mc RT nF concentration polarization be may dowered by increasing agitation and rising the electrolyte temperature. iL

to son Consentration. Polarisation Consentration polarisation of on electrode is a result of formation of Diff. - usion layer adjecent electrode surface where there is & gradient of the concentration Diffusion of Jons through the layers controls the controls the electrochemical reaction The electrode potential may be be calculated accounding to Nernst equation E Eo RT nE loge Sion here to standard electrode Potential gas constant R. I M. temperature = number of electrons trans - -Ifered by one ES Faraday constant molar cautivity of jons jon Cion