Electric double layer near electrode and electric field between electrode

In summary, when an electric field is applied across an electrolyte solution with charged particles, the particles move parallel or antiparallel to the field based on their charge. This is because almost all of the potential drop occurs at the double layer on each electrode, resulting in no electric field within the solution. However, there is still movement due to the balance of the electrostatic force and the Brownian motion of the particles. The potential drop across the electrolyte solution is dependent on electron transfer and there may be electric double layers present.
  • #1
wonderus
1
0
My question about electrochemistry is best phrase via an exercise in "Intermolecular and surface forces" by Israelachvili (although this is not my homework problem!):

When an electric field is applied across an electrolyte solution containing charged particles they are seen to move parallel or antiparallel to the field depending on the sign of their charge. Now, since almost all of the potential drop must occur across the double layer at each electrode surface, there can be no electric field within the conducting electrolyte solution and hence no force on the charged colloidal particles. Why, then, do the particles move?


When two electrodes applying an electric field across a membrane, is the potential drop across the electrolyte solution the same as that I have applied? I understand that the situation above applies only to charged electrodes without electron transfer. Suppose electron transfer takes place on one or both electrodes, would the potential drop across the electrolyte the same as what I applied? Are there any electric double layers in this case. Thanks.
 
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  • #2
Can someone tell me what happens if i have two strips(electrodes) of the same metal in an electrolyte. one connected to the -ve end of the battery(Vbias) and the other connected to the positive end.
 
  • #3
wonderus said:
My question about electrochemistry is best phrase via an exercise in "Intermolecular and surface forces" by Israelachvili (although this is not my homework problem!):

When an electric field is applied across an electrolyte solution containing charged particles they are seen to move parallel or antiparallel to the field depending on the sign of their charge. Now, since almost all of the potential drop must occur across the double layer at each electrode surface, there can be no electric field within the conducting electrolyte solution and hence no force on the charged colloidal particles. Why, then, do the particles move?


When two electrodes applying an electric field across a membrane, is the potential drop across the electrolyte solution the same as that I have applied? I understand that the situation above applies only to charged electrodes without electron transfer. Suppose electron transfer takes place on one or both electrodes, would the potential drop across the electrolyte the same as what I applied? Are there any electric double layers in this case. Thanks.

its is effective only to a certain pint in the solution...the electrostatic force
 

1. What is an electric double layer near an electrode?

An electric double layer refers to the layer of charge that forms at the interface between an electrode and an electrolyte solution. This layer is made up of two parts: the Helmholtz layer, which contains ions that are specifically adsorbed onto the electrode surface, and the diffuse layer, which contains ions that are attracted to the electrode by electrostatic forces.

2. How does the electric double layer affect the electrode's behavior?

The electric double layer plays a crucial role in determining the electrical properties of the electrode. It affects the capacitance, conductivity, and reactivity of the electrode, which in turn can influence the overall performance of an electrochemical system.

3. What is the electric field between an electrode and the electric double layer?

The electric field between an electrode and the electric double layer is the result of the charge separation that occurs within the double layer. It is strongest at the interface between the electrode and the electrolyte solution, and its strength decreases as you move away from the interface.

4. How is the electric field between an electrode and the electric double layer measured?

The electric field can be measured using a technique called cyclic voltammetry, which involves applying a small voltage to the electrode and measuring the resulting current. By analyzing the changes in current at different voltages, the electric field can be calculated.

5. What factors can affect the electric double layer near an electrode?

The electric double layer can be affected by a variety of factors, including the type and concentration of electrolyte, the surface characteristics of the electrode, and the applied voltage. Temperature, pressure, and the presence of impurities can also have an impact on the electric double layer.

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