Higher Rf Value? (TLC Chromatograpghy)

[negatifzeo]

Homework Statement

Suppose you carry out a TLC separation of acetaminophen and phenacetin on silica gel using a nonpolar developing solvent. Which should have the higher Rf value, and why?

Homework Equations

Im not sure. Is polarity a factor here? I don't think the polarity difference is that great here. Could molecular weight play a factor?

The Attempt at a Solution

 

[chemisttree]

It is mostly polarity. Look at the structures! Both structures contain the same aromatic acetamide functionality but Acetaminophen has a phenolic group whereas phenacetin has an aromatic ether on the aromatic ring. Can you estimate which will be most polar and least polar?