I wanted to thank you for taking the time to answer my elementary question on the salt bridge. Yes, what you say makes sense, in that if the concentration of the salt ions in the bridge is uniform and sufficiently high, we could think of ions of the same sign as chains connected along the bridge so that when a ion moves from the bridge into solution, the electromagnetic perturbation propagate to the other end so that the current is the same all along the bridge. (The same goes for ions of the other side, in opposite direction). What I was thinking about is: what if the concentration is high towards the ends of the bridge, and lower in the middle? Can I have release of positive ions on one side, release of negative ions on the other side and little to no current in the middle of the bridge until the electric field due to the charge imbalance becomes strong enough to cause drift inside the bridge? This could happen if the mobility of the ions is different in the bulk of the bridge w.r.t. the end sections where the the bridge interfaces with the solution. In case you are wondering, I have no special reasons to investigate this possible behavior except for the sheer curiosity of seeing if it is possible to 'break KCL' in a simple electrochemical cell. It should in theory be possible, since we can have a small transient current even when the bridge is broken in two (the reaction will stop very soon once the electric field builds up, preventing the release of further ions. I was only wondering if someone had quantified this effect, out of sheer curiosity.
This is a very interesting topic. So in electrochemistry we can use porous fritted glass to slow down the diffusion of ions between two separate chambers. In your case you could have 3 chambers connected via fritted glass. Each chamber would have a different concentration of electrolyte, but they would be ionically conducting. The question about putting positive charge on one side and negative charge on the other side only seems possible at electrode interfaces and even so the charge would be balanced by something else (like electrical double layer). I think in electrochemistry we assume that KCL holds which is why we describe things the way we do. But I don't know about measuring short term transient effects, that might occur faster than the time scale of the instrument speed.
I think this is a very general question and may be difficult to answer perfectly because when you talk about finding out "performance of the electrocatalyst" this could mean a lot of things. Very broadly, you can probably use almost any electrochemical technique to interrogate your electrocatalyst, including (but not necessarily limited to) chronoamperometry, cyclic voltammetry, impedance spectroscopy, pulse techniques, etc.
I wanted to thank you for taking the time to answer my elementary question on the salt bridge.
Yes, what you say makes sense, in that if the concentration of the salt ions in the bridge is uniform and sufficiently high, we could think of ions of the same sign as chains connected along the bridge so that when a ion moves from the bridge into solution, the electromagnetic perturbation propagate to the other end so that the current is the same all along the bridge. (The same goes for ions of the other side, in opposite direction). What I was thinking about is: what if the concentration is high towards the ends of the bridge, and lower in the middle? Can I have release of positive ions on one side, release of negative ions on the other side and little to no current in the middle of the bridge until the electric field due to the charge imbalance becomes strong enough to cause drift inside the bridge? This could happen if the mobility of the ions is different in the bulk of the bridge w.r.t. the end sections where the the bridge interfaces with the solution.
In case you are wondering, I have no special reasons to investigate this possible behavior except for the sheer curiosity of seeing if it is possible to 'break KCL' in a simple electrochemical cell.
It should in theory be possible, since we can have a small transient current even when the bridge is broken in two (the reaction will stop very soon once the electric field builds up, preventing the release of further ions. I was only wondering if someone had quantified this effect, out of sheer curiosity.
This is a very interesting topic. So in electrochemistry we can use porous fritted glass to slow down the diffusion of ions between two separate chambers. In your case you could have 3 chambers connected via fritted glass. Each chamber would have a different concentration of electrolyte, but they would be ionically conducting. The question about putting positive charge on one side and negative charge on the other side only seems possible at electrode interfaces and even so the charge would be balanced by something else (like electrical double layer). I think in electrochemistry we assume that KCL holds which is why we describe things the way we do. But I don't know about measuring short term transient effects, that might occur faster than the time scale of the instrument speed.
What to measure and how?
Measure the redox potential using cyclic voltammetry :)
What necessary techniques must be done to find out performance of electrocatalyst?Additionally how choronoamperometry helps us to find that?
I think this is a very general question and may be difficult to answer perfectly because when you talk about finding out "performance of the electrocatalyst" this could mean a lot of things. Very broadly, you can probably use almost any electrochemical technique to interrogate your electrocatalyst, including (but not necessarily limited to) chronoamperometry, cyclic voltammetry, impedance spectroscopy, pulse techniques, etc.