[Hgrigsby]

  well, thanks to all those people who tried to help me last time, although no one actually knew what to do...don't worry I finally got it.  Here is a new one.  

a student begins with 2.22g of salicylic acid (MW=138 g/mol) and 4.04 mL of acetic anhydride (MW=102g/mol density=1.081g/mL) in the preparation of aspirin.  

I was asked for the number of moles of salicylic acid and acetic acid, I got that.  The next question asks to find the limiting reagent.  How do I find that without the empirical formula?  I cheated and went online and looked up each empirical formula and found it that way so I know that salicylic acid is the limiting reagent, however, I need to know how to do it without the empirical formula.  Any guess on how I even begin?

[arnyk]

I think you would need to know at least the molecular formulas in order to write out the full equation in order to determine the limiting/excess reagents.