January 21, 2020, 08:45:07 AM
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### Topic: Time for dissolved IONs to migrate in a field.  (Read 315 times)

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#### fsonnichsen

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##### Time for dissolved IONs to migrate in a field.
« on: June 20, 2019, 01:37:04 PM »
I am trying to calculate some speeds for the migration of ions in solution under and electrical field. I have values of ionic mobilities for K+ for example of:
u=7.62E-8 (m**2/sV)
Take a typical voltage of 1.0 for plates separated by 1cm:
E=V/D = 1V/0.01m = 100(V/m)
Using:
speed(m/s) = u E
we have:
s=7.62E-8 x 100 = 7.62E-6 m/s = 7.62E-4 cm/s
To transverse the 1cm plates it would take
1/7.62E-4 = 1300 s or 20 minutes.

Seemed high-Does this sound reasonable?---I guess my intuition is weak here and I found no worked problems in the texts I have!
thanks
Fritz

#### Enthalpy

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##### Re: Time for dissolved IONs to migrate in a field.
« Reply #1 on: June 21, 2019, 09:28:43 AM »
OK.