HELP! HARDEST PROBLEM EVER! how do i balance this?

[ginjuicy]

The problem states:

"An actual yield of 1.86g of aspirin (C₉H₈O₄), along with a side-product of acetic acid (C₂H₃O₂), is obtained by heating 2.00g of salicylic acid(C₇H₆O₃) with 4.00g of acetic anhydride (C₄H₆O₃). Write the overall reaction equation, then determine the theoretical yield, as well as the percent yield. Then show the limiting reagent, and show all moles and mole/mole ratio's."



That was pretty much my reaction when i saw this problem!!!
I tried balancing it first...like so:
C₇H₆O₃+C₄H₆O₃=C₉H₈O₄+C₂H₃O₂
I entered this in the Chemical Balancer on this site and it came up with an error: "equation C₇H₆O₃+C₄H₆O₃=C₉H₈O₄+C₂H₃O₂ can be balanced in an infinite number of ways: this is a combination of two different reactions"

Have no idea what that means! Can someone help me get started??? It's asking me for so many things! Is the chemical equation at least right???
How do i balance it?

THANK YOU SOOO MUCH!

[Sam]

First of all acetic acid is C₂H₄O₂.

But anyway this reaction could be balanced in many ways if you do not impose any additional assumptions.
Knowing that acetic group (Ac = CH₃CO).is unchanged in the reaction is enough to balance it. First you rewrite it as:
C₇H₆O₃ + Ac₂O = AcC₇H₅O₃ + AcOH
and that is easy to balance:
http://www.webqc.org/balance.php?reacti ... 5O₃%2BAcOH

[ginjuicy]

Thank you so much!

No wonder i couldnt balance it...my professor had a typo for acetic acid!

This helps alot!