Limiting Cases of the General Solution

If all the binary dilfusion coefficients have the same value then we see from Eq. 8.3.25 that [A] degenerates to a scalar times the identity matrix 

The rate factor matrix [O] also is diagonal with all diagonal elements equal 

In fact, for this special case it is possible to derive an explicit relation for the molar fluxes (see Section 8.5 for further discussion). 

In presenting these last results we make use of the fact that if the mole fractions are 

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