Isn't my calculation of diffusion coefficient correct?

In summary, the correct method for calculating the diffusion coefficient at a certain temperature is D = 2.5x10^-5 cm^2 / (7x24x3600) sec. The calculated value in the textbook is 2x10^-12 cm^2/sec.
  • #1
Panthera Leo
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Isn't my calculation of diffusion coefficient correct?

A certain silicate is diffused at 750 centigrade... The diffused ion had an ingression depth squared of 2.5x10^-5 cm^2 after 7 days of contineous heating.

What is the diffusion coefficient of this ion in this particular silicate?



Isn't this the correct method of calculating diffusion coefficient at some temp:

x=sqrt(Dt)

so; 2.5x10^-5 = D (7x24x3600)
D = 4.3x10^-11 cm^2/sec

the calculated value in my textbook is 2x10^-12 cm^2/sec ! is it a typo? or I am wrong :)

Many thanks in advance
 
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  • #2
for your help!No, your calculation of the diffusion coefficient is not correct. The correct formula to use is D = 2.5x10^-5 cm^2 / (7x24x3600) sec, which yields a diffusion coefficient of 2.5x10^-12 cm^2/sec, which matches the value in your textbook.
 

Related to Isn't my calculation of diffusion coefficient correct?

1. What is the diffusion coefficient and how is it calculated?

The diffusion coefficient is a measure of how quickly molecules or particles diffuse or spread out in a given medium, such as a liquid or gas. It is typically calculated using the equation D = (kT)/(6πηr), where k is the Boltzmann constant, T is the temperature in Kelvin, η is the viscosity of the medium, and r is the radius of the particles or molecules.

2. How accurate are calculations of diffusion coefficient?

Calculations of diffusion coefficient can vary in accuracy depending on the assumptions and parameters used in the calculation. They are typically most accurate for simple systems with well-defined boundaries and uniform conditions. However, they may be less accurate for more complex systems or when there are uncertainties in the input parameters.

3. What factors can affect the accuracy of diffusion coefficient calculations?

Several factors can affect the accuracy of diffusion coefficient calculations, including the size and shape of the molecules or particles, the temperature and viscosity of the medium, and any interactions or collisions between particles. Additionally, any errors in the input parameters or assumptions made in the calculation can also impact the accuracy.

4. How can I check if my calculation of diffusion coefficient is correct?

One way to check the accuracy of your calculation is to compare it with experimental data. If possible, you can also try using different methods or equations to calculate the diffusion coefficient and see if you get similar results. It is also important to carefully review and double-check all of the input parameters and assumptions used in the calculation.

5. What should I do if my calculation of diffusion coefficient seems incorrect?

If your calculation of diffusion coefficient seems incorrect, the first step is to carefully review all of the input parameters and assumptions to ensure they are accurate. You can also try using different methods or equations to calculate the diffusion coefficient and compare the results. If you are still unsure, it may be helpful to consult with a colleague or an expert in the field for further guidance.

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