DETERMINATION OF DIFFUSIVITY

Example 17.2-1 Determination of Diffusivity for a Specific Pair of Gases

To solve this example problem, we want to determine D[CCl4-O2], the diffusivity of carbon tetrachloride into oxygen from page 526-527 of BSL.

Since we are given the system pressure, we find it convenient to use equation 17.2-15a which relates mass transfer rate to pressure, but we must rearrange it to solve for diffusivity.

Notice that in order to solve this, we need data values for:

N[CCl4] (rate of mass transfer of CCl4 into O2)
R (gas constant)
T (temperature)
p (total pressure)
pB2 (partial pressure of oxygen in pure oxygen phase)
pB1 (partial pressure of oxygen at oxygen-carbon tetrachloride interface)

We are given all these values EXCEPT N[CCl4], which we can calculate from the evaporation rate data given.

We now have all the necessary data to complete this problem. Just enter book values and then ask for DAB (D[CCl4-O2]).

Thanks for visiting this example problem page! This was created for a chemical engineering mass and energy transport class (CENG 402) at Rice University. The textbook referred to is BSL (Bird, Stewart and Lightfoot) and is taught by Dr. S. Davis. Email questions to Dr. Davis.
Email your comments to me, Jenna L. Hutchins, a former student of this course!