Question

Consider the following four formulas: SO₂, B₂H₆, CO, C₄H₂O₂. Which of these formulas could be.

a) only an empirical formula
b) only a molecular formula
c) either a molecular or an empirical formula

Answer 1

The empirical formula represents the simplest whole-number ratio of atoms in a compound, while the molecular formula gives the actual number of atoms of each element in a molecule. If the molecular formula is a whole-number multiple of the empirical formula, it could be either a molecular or an empirical formula. If the molecular formula and the empirical formula are the same, it could be only an empirical formula.

Step-by-step explanation:

The empirical formula represents the simplest whole-number ratio of atoms in a compound, while the molecular formula gives the actual number of atoms of each element in a molecule. To determine if a formula could be only an empirical formula, only a molecular formula, or either, we need to compare the molecular formula to the empirical formula. If the molecular formula is a whole-number multiple of the empirical formula, then it could be either a molecular or an empirical formula. If the molecular formula and the empirical formula are the same, then it could be only an empirical formula.

Let's analyze each formula:

• SO₂: This formula is a molecular formula and cannot be simplified into a smaller whole-number ratio. Therefore, it could be either a molecular or an empirical formula.
• B₂H₆: This formula is a molecular formula and cannot be simplified into a smaller whole-number ratio. Therefore, it could be either a molecular or an empirical formula.
• CO: This formula is a molecular formula and cannot be simplified into a smaller whole-number ratio. Therefore, it could be either a molecular or an empirical formula.
• C₄H₂O₂: This formula is a molecular formula but can be simplified into a smaller whole-number ratio. The empirical formula of C₄H₂O₂ is CH₂O. Therefore, this formula could be only an empirical formula.