Final answer:
Compounds with the same empirical formula may have different molecular formulas, as an empirical formula is the simplest whole-number ratio of atoms in a compound. Isomers have identical molecular formulas but different structures and properties. If a compound's molecular formula cannot be simplified, it is also its empirical formula.
Step-by-step explanation:
Compounds that have the same empirical formula may not necessarily have the same molecular formula. An empirical formula represents the simplest whole-number ratio of atoms in a compound, whereas the molecular formula shows the actual number of atoms of each element in a molecule of the compound. For instance, both glucose (C6H12O6) and ribose (C5H10O5) have the same empirical formula, CH2O, since the molecular formulas can both be simplified to this ratio. Isomers are different compounds that have the same molecular formula but differ in structural arrangement or configuration, leading to different properties. Examples include butane and isobutane, which both have the molecular formula C4H10, yet they are distinct compounds with different boiling points due to their different structures. In cases where the molecular formula of a compound cannot be simplified into a smaller whole-number ratio, like H2O or P2O5, the empirical formula is identical to the molecular formula. Therefore, for carbon dioxide, the empirical formula and the molecular formula are both CO2.