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Chemistry Forums for Students => Physical Chemistry Forum => Topic started by: elifkorkmaz on May 01, 2020, 06:24:02 AM

Title: Groundwater pollution
Post by: elifkorkmaz on May 01, 2020, 06:24:02 AM
an impoundment 7x4 m is contaminated by carbontetrachloride. The contaminated liquid comes in contact with the groundwater and a concentration gradient of 1.1x10-6 (mol/cm3)/cm is established. Use Fick’s law to determine the diffusive flux assuming diffusion is the only driving force. How many kilograms of carbontetrachloride will move toward the groundwater in one hour?
Title: Re: Groundwater pollution
Post by: sjb on May 01, 2020, 09:21:24 AM
an impoundment 7x4 m is contaminated by carbontetrachloride. The contaminated liquid comes in contact with the groundwater and a concentration gradient of 1.1x10-6 (mol/cm3)/cm is established. Use Fick’s law to determine the diffusive flux assuming diffusion is the only driving force. How many kilograms of carbontetrachloride will move toward the groundwater in one hour?

What have you tried?
Title: Re: Groundwater pollution
Post by: elifkorkmaz on May 01, 2020, 10:29:39 AM
I hav tried to find Diffusion coefficient and flux, but I couldnt find the movement in 1hour...
Title: Re: Groundwater pollution
Post by: Corribus on May 01, 2020, 11:35:01 AM
Without being given the diffusion constant, I don't see how to express an answer in absolute terms. However you can express it in terms of the diffusion constant. There is no way to calculate the diffusion constant from the information given. It is a characteristic property of the diffusant and diffusing medium. (You can determine D from the flux, or the flux from D. Both are unknowns here. So the best you can do is express the flux in terms of D, and then calculate the total mass moved - in terms of D - from the flux.)
Title: Re: Groundwater pollution
Post by: elifkorkmaz on May 01, 2020, 12:50:25 PM
I found flux by Fick's law, but how can ı find the movwmwnt of contaminant in 1hour?
Title: Re: Groundwater pollution
Post by: Corribus on May 01, 2020, 01:39:15 PM
What are the units of flux?
Title: Re: Groundwater pollution
Post by: elifkorkmaz on May 01, 2020, 02:16:24 PM
I found FİRSTLY D=5.06x10^-7 x T / μ x V^0.6
after that from fick's law ; -Dx (dc/dx)
and ı got an answer
Title: Re: Groundwater pollution
Post by: Corribus on May 01, 2020, 02:22:49 PM
Great work. Where did you find the diffusion constant?
Title: Re: Groundwater pollution
Post by: elifkorkmaz on May 01, 2020, 02:29:14 PM
where should ı use it?