Question

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

Answer 1

The answer is C3H603 and C2H402.

Answer 2

Answer: $C_2H_6$ and $CH_4$

Explanation:

Molecular formula is the chemical formula which depicts the actual number of atoms of each element present in the compound.  

Empirical formula is the simplest chemical formula which depicts the whole number of atoms of each element present in the compound.

$C_2H_6$ and $C_4H_{12}$ both have empirical formulas of $CH_3$

$C_3H_6O_3$ and $C_2H_4O_2$ both have empirical formulas of $CH_2O$  

$C_2H_6$ and $CH_4$  have empirical formulas $CH_3$ and $CH_4$ respectively.

$CH_2O$ and $C_3H_6O_3$ both have empirical formulas of $CH_2O$