A compound consists of 37.51 g of C, 8.38 g of H, and 54.11 g of O. What is the molar mass of the compound if its empirical formula is C3H8O2 and its molecular formula is a multiple of the empirical formula?

• A. 60.0 g/mol
• B. 46.1 g/mol
• C. 74.1 g/mol
• D. 92.1 g/mol

Answer: (D)

Verified step by step guidance

1. Calculate the empirical formula mass by summing the atomic masses of all atoms in the empirical formula C3H8O2. Use atomic masses: C = 12.01 g/mol, H = 1.008 g/mol, O = 16.00 g/mol. The formula is: \(\text{Empirical formula mass} = 3 \times 12.01 + 8 \times 1.008 + 2 \times 16.00\).
2. Determine the total mass of the compound given by the sum of the masses of C, H, and O: \$37.51 + 8.38 + 54.11$ grams.
3. Calculate the moles of each element by dividing the mass of each element by its atomic mass: \(\text{moles C} = \frac{37.51}{12.01}\), \(\text{moles H} = \frac{8.38}{1.008}\), \(\text{moles O} = \frac{54.11}{16.00}\). This step helps confirm the empirical formula if needed.
4. Use the empirical formula mass and the given molecular formula information to find the molar mass of the compound. Since the molecular formula is a multiple of the empirical formula, the molar mass is \(n\) times the empirical formula mass, where \(n\) is an integer.
5. Compare the calculated molar mass with the given options to identify the correct molar mass of the compound.