Which of the following statements about empirical and molecular formulas is correct?

• A. The empirical formula gives the exact number of atoms of each element in a molecule.
• B. The molecular formula is always identical to the empirical formula.
• C. The empirical formula represents the simplest whole-number ratio of atoms in a compound.
• D. Empirical formulas can contain fractional subscripts.

Answer: (C)

Verified step by step guidance

1. Understand the definition of an empirical formula: it represents the simplest whole-number ratio of atoms of each element in a compound, not necessarily the exact number of atoms.
2. Recognize that the molecular formula shows the actual number of atoms of each element in a molecule, which can be a multiple of the empirical formula.
3. Note that the empirical formula cannot have fractional subscripts because it must represent whole-number ratios.
4. Recall that the molecular formula is not always identical to the empirical formula; it can be the same or a whole-number multiple of it.
5. Conclude that the correct statement is: 'The empirical formula represents the simplest whole-number ratio of atoms in a compound.'