Which molecular formula is correctly paired with its corresponding empirical formula?

• A. N2O4 : NO3
• B. C6H12O6 : CH2O
• C. C4H10 : C2H5
• D. C2H6 : CH3

Answer: (B)

Verified step by step guidance

1. Understand the difference between molecular and empirical formulas: The molecular formula shows the actual number of atoms of each element in a molecule, while the empirical formula shows the simplest whole-number ratio of atoms in the compound.
2. For each given molecular formula, determine the empirical formula by dividing the subscripts of each element by their greatest common divisor (GCD).
3. Check the pair N2O4 : NO3. Calculate the GCD of 2 and 4, which is 2. Divide each subscript by 2 to get NO2, not NO3, so this pair is incorrect.
4. Check the pair C6H12O6 : CH2O. The GCD of 6, 12, and 6 is 6. Dividing each subscript by 6 gives CH2O, which matches the empirical formula, so this pair is correct.
5. Similarly, verify the other pairs by finding the GCD of their subscripts and dividing to find the empirical formula, then compare to the given empirical formula to confirm correctness.