Further Physical Chemistry: Electrochemistry session 9
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- Опубликовано: 1 окт 2024
- The ninth video supporting the electrochemistry content from Further Physical Chemistry.
This course is based heavily on my undergraduate learnings from CP Wilde, Department of Chemistry, Imperial College London in the early 2000s!
Table of Contents:
00:05 - The overpotential: A recap
00:50 - Overpotentials and galvanic cells
01:41 - Cell performance with overpotential
02:39 - Cell performance with overpotential
03:35 - Free energy in the galvanic cell
05:13 - Overpotentials and electrolytic cells
05:52 - Cell performance with overpotential
06:52 - Free energies in the electrolytic cell
07:39 - Galvanic vs electrolytic cells
08:25 - Kinetics vs Thermodynamics
09:52 - Effect of electrode kinetics
10:51 - Effect of electrode kinetics
11:46 - The real world: the chlor-alkali industry
13:36 - Summary
This video is very helpful! Explanations are clear and complete, thank you very much for the work you have done, that were explanations I was looking for!
Really good series. Thank you very much
ThankYou. It is highly helpful for understanding the concepts!
Speechless
the videos are really fantastic !!!!!
Thank you very much
Glad you like them!
Thanks for making these videos available to the outside world. They are exceptionally well done.
Some *minor* exposition-related feedback: always, always make sure that axes are labeled. And make the distinction between curves clearer. In the last example you switched solid and dashed lines (because of course you use a solid line to mark the dominant reaction) - it tricks the brain into thinking that the solid line is the same reaction from the previous graph. Adding a label to the raising trait of the curves would make following the reasoning easier.
In the end, thermodynamics sets the 'starting points' of the curves, while kinetics dictates how fast the curves rise, so who wins depends on both. Doubling the labels would make this evident at a glance.
Really hulpful explanations for those theories.
at 5.12, according to the diagram, At Ecell = 0, it must correspond to some equal and opposite currents. But we know that when voltage is zero,current won't flow.. Is it capacitve current? if so, how are we measuring the capacitive current?
I think you are becoming confused with "voltage" and "cell potential". If you measure across a standard R6 cell (AA), you will measure a potential difference of ~1.3-1.5 V. But this doesn't mean a current is flowing; it just means there is a difference in the potential across the terminals. When the potential difference drops to zero, it means the potential of the two terminals is now equal and there will be no thermodynamic driving force for any electron transfer.
Yes, the diagram suggests that, for a sufficiently high current, there would be an effective cell potential of zero, however it is impractical to get to this high a current and in practice would not occur.
To hold a cell at a potential of zero, your potentiostat must apply a potential equal and opposite to the cell's equilibrium potential. No current will flow, and the only "current" is the exchange current at the electrode surfaces. There is no capacitive current in this example.
Amazing video thank you
Can I get this in pdf ?
Great explanation