Which pair consists of a molecular formula and its corresponding empirical formula?
(1) C2H2 and CH3CH3 (3) P4O10 and P2O5
(2) C6H6 and C2H2 (4) SO2 and SO3
3) P4O10 and P2O5 The mass of the P4O10 divided by the mass of the P2O5=2, and if you multiply the number of atoms in the P2O5 by 2, you get the P4O10, thus P2O5 is its empirical formula.