The empirical formula is C₂H₄O₃.
We must calculate the <em>masses of C, H, and O</em> from the masses given.
<em>Mass of C</em> = 32.75 g CO₂ × (12.01 g C/44.01 g CO₂) = 8.9372 g C
<em>Mass of H</em> = 13.4 g H₂O × (2.016 H/18.02 g H₂O) = 1.5067 g H
<em>Mass of O</em> = Mass of compound - Mass of C - Mass of H
= (28.30 – 8.9372 – 1.5067) g = 17.856 g
Now, we must convert these <em>masses to moles</em> and <em>find their ratio</em>s. If the ratios are not integers, we <em>multiply them by a number</em> to make them close to integers.
From here on, I like to summarize the calculations in a table.
<u>Element</u> <u> m/g </u> <u> n/mol </u> <u> Ratio </u> <u> ×2 </u> <u>Integers</u>
C 8.9372 0.74415 1 2 2
H 1.5067 1.4948 2.0086 4.0174 4
O 17.856 1.1160 1.4997 2.9994 3
The empirical formula is C₂H₄O₃.