CHEMISTRY
posted by irfan .
1. The percent composition by mass for peroxyacylnitrate (PAN) is:19.8% C,2.5% N, and the rest is oxygen. Determine the empirical formula of this compound.
...plz i really need your help!!!

Take 100 g sample.
19.8g C
2.5g N
77.7g O.
Convert to mols.
19.8/12 = ?
2.5/1 = ?
77.7/16 = ?
Now find the ratio of the elements to each other with the smallest being no smaller than 1.00.
The easy way to do that is to divide the smallest number by itself followed by dividing the other numbers by the same small number. Round to whole numbers but remember not to round too much; i.e., no more than 0.1 or so.