Liquid junction potential

In summary, the conversation discusses the concept of liquid/liquid junction potential between two liquids of the same composition but different concentrations. It is stated that this potential is not measurable in the absence of an external electrical circuit and electrodes. However, it is acknowledged that the potential exists based on theory and mechanisms. The topic is compared to similar phenomena at metal-metal conductor junctions and in batteries.
  • #1
somasimple
Gold Member
766
5
TL;DR Summary
Liquid junction potential question
Hi,
Is there a liquid/liquid junction potential between two liquids of same composition but different concentrations WHEN there is no external electrical circuit and then NO electrodes? (Of course this potential is not measurable).

Thanks,
 
Chemistry news on Phys.org
  • #3
Well, the links you gave show electrodes then there is a RedOx reaction with charge transfer within the external circuit. That is not my question.
 
  • #4
somasimple said:
Summary:: Liquid junction potential question

Of course this potential is not measurable
If something is not detectable, then how would anyone know?
 
  • #6
Yes, from the mechanism it exists even without being measured.
 
  • #7
Thanks for this reply.
 
  • #9
Thanks again Atyy,
The same phenomenon applies to batteries. They have an internal EMF even if they are not connected but one can not know their inner potential without connecting them. The charge separation creates an Electric field also called an electroneutrality field. It is the force that let's the things in place.
 

1. What is a liquid junction potential?

A liquid junction potential is a type of electrical potential that occurs at the interface between two different electrolyte solutions. It is caused by the difference in concentration and composition of ions in the two solutions, which creates a charge separation at the junction.

2. How does a liquid junction potential affect electrochemical measurements?

A liquid junction potential can affect electrochemical measurements by introducing an additional potential difference that can interfere with the accurate measurement of the desired potential. This can lead to errors in the measurement and affect the overall accuracy of the experiment.

3. Can a liquid junction potential be eliminated?

No, a liquid junction potential cannot be completely eliminated. However, it can be minimized by using a reference electrode with a similar electrolyte solution to the sample being measured, or by using a salt bridge to connect the two solutions and reduce the potential difference at the junction.

4. Are there any factors that can affect the magnitude of a liquid junction potential?

Yes, the magnitude of a liquid junction potential can be affected by several factors including the types and concentrations of ions in the solutions, the temperature, and the type of electrolyte used.

5. How can a liquid junction potential be corrected for in electrochemical measurements?

A liquid junction potential can be corrected for by using a double-junction reference electrode, which has an additional compartment filled with a concentrated electrolyte solution to minimize the potential difference at the junction. Alternatively, the measured potential can be corrected using mathematical equations based on the known composition of the solutions and the properties of the junction.

Similar threads

Replies
3
Views
1K
Replies
6
Views
2K
  • Chemistry
Replies
1
Views
750
  • Chemistry
Replies
3
Views
1K
  • Classical Physics
Replies
10
Views
1K
  • Chemistry
Replies
6
Views
1K
  • Chemistry
Replies
16
Views
3K
Replies
8
Views
3K
Replies
2
Views
954
Back
Top