Final answer:
The empirical formula is the simplest whole-number ratio of elements in a compound, found by dividing the molar amounts of each element by the smallest value among them. For instance, glucose's empirical formula is CH₂O, based on its composition of carbon, hydrogen, and oxygen.
Step-by-step explanation:
The empirical formula of a compound represents the simplest whole-number ratio of the elements within it. To find the empirical formula given grams of CO₂ and H₂O, you first need to calculate the molar amounts of carbon, hydrogen, and oxygen. Then, you divide each by the smallest amount to find the simplest whole-number ratio. For example, glucose has a molecular formula of C₆H₁₂O₆. The simplest whole-number ratio is 1:2:1 for carbon to hydrogen to oxygen, which gives an empirical formula of CH₂O.
Assuming the combustion of benzene and using the mentioned example of xylene, when you perform the combustion analysis, you would end up measuring the grams of CO₂ and H₂O produced, helping to determine the empirical formula of the original compound. Using these methods, we can determine that the empirical formula for a compound containing 40.0% C, 6.71% H, and 53.28% O is also CH₂O.