Answer
2 molecules that have different molecular formulas but have the same empirical formula are ribose and glucose.
Work Step by Step
Ribose has a molecular formula of $C_{5}H_{10}O_{5}$, while glucose has a molecular formula of $C_{6}H_{12}O_{6}$. Since the ratio of carbon to hydrogen to oxygen is the same in both molecules, the empirical formula of both must be the same. However, it is obvious that their actual molecular formula is different.
