ELectrochemical sensing problem

In summary, electrochemical sensing is a method of detecting and measuring chemical reactions using electrical signals. It involves converting a chemical reaction into an electrical signal, which is then measured and analyzed. The process involves the use of electrodes in a solution or sample, and offers advantages such as high sensitivity, selectivity, and speed. The most common types of electrochemical sensors are potentiometric, amperometric, and conductometric. Electrochemical sensing has a wide range of applications in fields such as environmental monitoring, biomedical research, and industrial processes.
  • #1
vinke
1
0
Anyone knows how to derive Fick's law of diffusion:

I=Jmf

Given current density applied to electrochemical sensing:
I= nAve

where :
I=current
J=flux
m=number of electrons
F=faraday constant
v=speed of particles
n=number of charge carriers/vol
A= cross-sectional area of sensor(electrode)
e=charge of an electron


Please help, at least give a clue where to start and the procedings.
Thanx
 
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  • #2
Peruse through these...

http://www.smecc.org/r.m.r_fick's_law.htm

http://www.webcom.com/rphair/bis/resources/cybertext/chapter7.html [Broken]
 
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  • #3


Fick's law of diffusion is a fundamental equation in the field of electrochemistry that describes the movement of particles, such as ions, through a solution. It is derived from the principles of mass transport and can be applied to electrochemical sensing problems.

To derive Fick's law of diffusion, we can start with the definition of flux (J) as the amount of particles passing through a unit area per unit time. In electrochemistry, this can be expressed as:

J = nAv

Where:
n = number of particles per unit volume
A = cross-sectional area of the sensor
v = velocity of the particles

Next, we can consider the current (I) applied to the electrochemical sensing system. This current is a result of the movement of charged particles, such as ions, through the solution. It can be expressed as:

I = nAve

Where:
e = charge of an electron

By substituting this expression for current into the equation for flux, we get:

J = I/v

Now, we can introduce Fick's law of diffusion, which states that the flux of particles is directly proportional to the concentration gradient of the particles. This can be expressed mathematically as:

J ∝ ∂c/∂x

Where:
c = concentration of particles
x = distance

Combining this with our previous equation for flux, we get:

J = -D ∂c/∂x

Where:
D = diffusion coefficient

Finally, we can combine this with our equation for current to derive Fick's law of diffusion for electrochemical sensing:

I = -DA ∂c/∂x

This equation shows that the current (I) is proportional to the diffusion coefficient (D), the cross-sectional area of the sensor (A), and the concentration gradient (∂c/∂x) of the particles. This relationship is the basis for understanding the movement of particles in electrochemical sensing systems and can be used to design and optimize these systems for various applications.
 

1. What is electrochemical sensing?

Electrochemical sensing is a method of detecting and measuring chemical reactions using electrical signals. It involves converting a chemical reaction into an electrical signal, which can then be measured and analyzed.

2. How does electrochemical sensing work?

Electrochemical sensing involves the use of electrodes, which are placed in a solution or sample containing the chemical of interest. When the chemical reacts with the electrode, it produces an electrical signal that can be measured and analyzed.

3. What are the advantages of electrochemical sensing?

Electrochemical sensing offers several advantages, including high sensitivity, selectivity, and speed. It also requires minimal sample preparation and can be performed in real-time, making it a valuable tool for a wide range of applications in various fields such as environmental monitoring, biomedical research, and industrial processes.

4. What are the common types of electrochemical sensors?

The most common types of electrochemical sensors include potentiometric, amperometric, and conductometric sensors. Potentiometric sensors measure potential difference between two electrodes, amperometric sensors measure current flow between two electrodes, and conductometric sensors measure changes in electrical conductivity of a solution.

5. What are some applications of electrochemical sensing?

Electrochemical sensing has a wide range of applications, including environmental monitoring, food safety testing, medical diagnostics, and drug development. It is also used in chemical and biological research, as well as in various industrial processes such as corrosion monitoring and quality control.

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