EXAMPLE Calculate the liquid junction potential for contact ofo.1MHCI andoImKcl at 250C. Common anion so negative and E1=-0.025916ln (349.82+7634)/(73.52+76.34)=-0.0259 *1n2.84=-27mV
EXAMPLE Calculate the liquid junction potential for contact of 0.1 M HCl and 0.1 M KCl at 250C. Common anion so negative and EJ = - 0.025916 ln ((349.82+76.34)/(73.52+76.34)) = - 0.0259 * ln 2.84 = - 27 mV
Type 3-the General Case 2 solutions of different electrolyte at different concentrations in contact with each other Region l Region 2 0.1M0.05M From table 2.3.3 HCI KNO3 uH+=3625 CI- 7.912 ux=7619 K +NO3 NO3 =7.404
Type 3 - the General Case 2 solutions of different electrolyte at different concentrations in contact with each other From table 2.3.3: uH+ = 36.25 uCl- = 7.912 uK+ = 7.619 uNO3- = 7.404 0.1 M HCl 0.05 M KNO3 H+ ClK+ NO3 - Region 1 Region 2
Mass Transport- Revisited Recall 3 modes Diffusion Migration Convection If use short times(< 10 s) and dont stir (quiescent), then i=id+i
Mass Transport - Revisited Recall 3 modes: Diffusion Migration Convection If use short times ( < 10 s) and don’t stir (quiescent), then i = id + im
Consider Sign of, and i Consider current for quiescent solutions of (a)Cut, and(b) cu(CN)42- at negatively charged electrodes Cu2+ Cu(CN)42 Conclusion: i and i do not have to be in same direction
Consider current for quiescent solutions of (a)Cu2+; and (b) Cu(CN)4 2- at negatively charged electrodes: Conclusion: id and im do not have to be in same direction Consider Sign of id and im _ id im im id Cu2+ Cu(CN)4 2- _
EXAMPLE Identify and give sign for all contributions to current for quiescent solutions of Cu(Cn)2 at a negatively charged electrode l?? Cu(CN)2 2?
Identify and give sign for all contributions to current for quiescent solutions of Cu(CN)2 at a negatively charged electrode: EXAMPLE _ Id ?? Im ?? Cu(CN)2