Hi Dr Andrew, great videos and presentation skills. However, I realized that in this serious of Further Physical Chemistry videos you related to lots of other Y1 and Y2 contents, is it possible for you to upload those videos? Really appreciate your help.
I'm from korea and I'm really appreciating your series, but i have one questions. you said that only neutral species are in subjected to diffusion, then aren't there any diffusion of ion? if there is concentration gradient of Cu2+, then there is no diffusion of Cu2+ but only migration occurs?
Yes; I can see that is confusing. Diffusion is driven solely by the concentration gradient. While a concentration gradient of ions can (and indeed does) exist, ionic migration moderated by an electric field far outweighs this; an imposed electric field causes ionic migration (cations to cathode, anions to anode) and in fact *creates* a concentration gradient of ions; any diffusion process is therefore eliminated. Remember that the the ions themselves create an electric field which, in the absence of the imposed field, will cause migration of the ions. Hope that clears things up - Glad you're finding the videos useful.
@@aw_mckinley I had the same doubt and your explaination here that the migration outweighs diffusion is helpful. I am reading literature related to DFN model of lithium ion battery, which has partial derivatives with linking diffusion and migration(not surely if its exactly like that I am still trying to understand), so my question is the movemnet of lithium ion with its solvation shell will be considered as diffusion or migration? Does lithium ion with its solvation shell carry any charge or not?
Apologies for delay in response. It's not clear where in the video you are referring. At 7:30 I have a diagram showing flow of anions (negatively charged ions) going to the positive electrode - this is correct. Likewise the flow of cations(positively charged) going to the negative electrode. I have however made a mistake in the "flow of electrons"! The potentiostat I drives these to the cathode (negative electrode) and keeps the cathode as a "pool of electrons". Thank you for flagging this - it made me revisit the video!
Hello! Mr Andrew McKinley, it would be quite better if you provide with English Subtitles!! Please consider it!!
I think you can turn on the RUclips auto-generated subtitles? I haven't checked them recently, but I remember them being pretty good. Hope that helps,
I love your work and appreciate your effort. Pristine explanation.
Hi Dr Andrew, great videos and presentation skills. However, I realized that in this serious of Further Physical Chemistry videos you related to lots of other Y1 and Y2 contents, is it possible for you to upload those videos? Really appreciate your help.
Thanks a lot for the series. Very intuitive and useful.
Glad you found it useful :-)
I'm from korea and I'm really appreciating your series,
but i have one questions. you said that only neutral species are in subjected to diffusion, then aren't there any diffusion of ion?
if there is concentration gradient of Cu2+, then there is no diffusion of Cu2+ but only migration occurs?
Yes; I can see that is confusing. Diffusion is driven solely by the concentration gradient. While a concentration gradient of ions can (and indeed does) exist, ionic migration moderated by an electric field far outweighs this; an imposed electric field causes ionic migration (cations to cathode, anions to anode) and in fact *creates* a concentration gradient of ions; any diffusion process is therefore eliminated. Remember that the the ions themselves create an electric field which, in the absence of the imposed field, will cause migration of the ions.
Hope that clears things up - Glad you're finding the videos useful.
@@aw_mckinley
Your explanation really touched me.
I cannot be more grateful than this
Thank you very very much.
@@aw_mckinley I had the same doubt and your explaination here that the migration outweighs diffusion is helpful. I am reading literature related to DFN model of lithium ion battery, which has partial derivatives with linking diffusion and migration(not surely if its exactly like that I am still trying to understand), so my question is the movemnet of lithium ion with its solvation shell will be considered as diffusion or migration? Does lithium ion with its solvation shell carry any charge or not?
Such a good presentation. Thank you soo much :)
You're very welcome!
Is the flow direction of anion and cation reversed?
Apologies for delay in response. It's not clear where in the video you are referring.
At 7:30 I have a diagram showing flow of anions (negatively charged ions) going to the positive electrode - this is correct. Likewise the flow of cations(positively charged) going to the negative electrode.
I have however made a mistake in the "flow of electrons"! The potentiostat I drives these to the cathode (negative electrode) and keeps the cathode as a "pool of electrons".
Thank you for flagging this - it made me revisit the video!