The empirical formula of a compound is CH. If the molecular mass of the compound is about 78 g, what is its molecular formula?

Answer

To find the molecular formula from the empirical formula and the molecular mass, follow these steps: 1. Calculate the empirical formula mass: For the empirical formula CH, the atomic mass of Carbon (C) is approximately 12.01 g/mol and Hydrogen (H) is approximately 1.008 g/mol. Empirical formula mass = 12.01 + 1.008 = 13.018 g/mol. 2. Determine the ratio (n) of the molecular mass to the empirical formula mass: n = (Molecular Mass) / (Empirical Formula Mass) = 78 g/mol / 13.018 g/mol ≈ 6. 3. Multiply the subscripts in the empirical formula by this ratio to get the molecular formula: Molecular formula = (CH) * 6 = C6H6. Therefore, the molecular formula is C6H6.