Determine the empirical formula of a compound containing 40.6 grams of carbon, 5.1 grams of hydrogen, and 54.2 grams of oxygen. In an experiment, the molar mass of the compound was determined to be 118.084 g/mol. What is the molecular formula of the compound? For both questions, show your work or explain how you determined the formulas by giving specific values used in calculations.

Explanation:

Mass of Carbon = 40.6g

Moles of Carbon

= 40.6g / (12g/mol) = 3.38mol

Mass of Hydrogen = 5.1g

Moles of Hydrogen

= 5.1g / (1.008g/mol) = 4.96mol

Mass of Oxygen = 54.2g

Moles of Oxygen

= 54.2g / (16g/mol) = 3.39mol

Mole ratio of Carbon : Hydrogen : Oxygen

= 3.38 : 4.96 : 3.39 ≈ 2 : 3 : 2.

Therefore empirical formula of compound

= C2H3O2.

Relative molecular mass

= 2(12) + 3(1.008) + 2(16) = 59.024

Since the actual molecular mass (118.084) is 2 times the relative molecular mass,

Molecular formula of compound = C4H6O4.