I struggle to understand the use of ion-permeable membrane (or salt bridge). https://en.wikipedia.org/wiki/Concentration_cell
If i pour two solutions with different concentration, why do you need the junction between solutions ? Like this :
According to my readings on Galvani's potential the electrode should be polarised with the potential of the solution their in. Hence you can calculate the concentration of unkown solution C2 without junction ?
In this page https://en.wikipedia.org/wiki/Salt_bridge it is said that the salt bridge is needed to avoid having one solution depleted of electrons and another full. Why the connection of electrode isn't creating equilibrium between solutions ?