Write wilke Chang eqution what is it application?

The wilke chang equation is basically used to determine the diffusion rate of something in a binary substance.

look here

google.com/books?id=F0kCdNhCpzUC&pg=PA201&lpg=PA201&dq=wilke+chang&source=bl&ots=K15Q9tOFo4&sig=aj3Lgj2XFmLsWVlrrY9ZdV_utVY&hl=en&ei=XXLaStqLI4Pl8Qbi2oy3BQ&sa=X&oi=book_result&ct=result&resnum=3&ved=0CA4Q6AEwAg#v=onepage&q=wilke%20chang&f=false">http://books.google.com/books?id=F0kCdNhCpzUC&pg=PA201&lpg=PA201&dq=wilke+chang&source=bl&ots=K15Q9tOFo4&sig=aj3Lgj2XFmLsWVlrrY9ZdV_utVY&hl=en&ei=XXLaStqLI4Pl8Qbi2oy3BQ&sa=X&oi=book_result&ct=result&resnum=3&ved=0CA4Q6AEwAg#v=onepage&q=wilke%20chang&f=false