Which of the following pairs does not share the same empirical formula?

C2H6 and C4H12 C3H6O3 and C2H4O2 C3H8O and CH2O C2H8 and CH4

empirical formula is the simplest ratio of whole numbers of components making up a compound

molecular formula is the actual number of components making up the compound

there can be many compounds having the same empirical formula

given options

1. C₂H₆ and C₄H₁₂

ratio of C to H in C₂H₆ - 2:6 - - > 1:3

C₄H₁₂ - 4:12 - - > 1:3

the simplified ratios for both are same

therefore both have same empirical formulas

2. C₃H₆O₃ and C₂H₄O₂

ratio of C to H to O in C₃H₆O₃ - 3:6:3 - - > 1:2:1

C₂H₄O₂ - 2:4:2 - - > 1:2:1

both have same empirical formulas

3. C₃H₈O and CH₂O

ratio of C to H to O in C₃H₈O - 3:8:1

CH₂O - 1:2:1

the 2 ratios of atoms are different which means they have different empirical formulas

4. C₂H₈ and CH₄

ratio of C to H in C₂H₈ - 2:8 - - > 1:4

CH₄ - - 1:4

2 ratios are same so same empirical formula

correct answer is 3. C₃H₈O and CH₂O they do not share the same empirical formula