Final answer:
The molecular formula is C₆H₈.
Step-by-step explanation:
To find the molecular formula, we need to compare the molar mass of the compound to the empirical formula mass. In this case, the molar mass is given as 168.0 g/mol and the empirical formula is C₄H₄. The empirical formula mass can be calculated by adding up the atomic masses of the elements in the formula: C (12.01 g/mol) + H (1.01 g/mol) x 4 = 16.05 g/mol.
Since the molar mass is approximately 10 times greater than the empirical formula mass, we can multiply the empirical formula by 10 to get the molecular formula. Therefore, the molecular formula is C₆H₈.
In chemistry, the molar mass (M) of a chemical compound is defined as the ratio between the mass and the amount of substance (measured in moles) of any sample of said compound. The molar mass is a bulk, not molecular, property of a substance. The molar mass is an average of many instances of the compound, which often vary in mass due to the presence of isotopes.
Most commonly, the molar mass is computed from the standard atomic weights and is thus a terrestrial average and a function of the relative abundance of the isotopes of the constituent atoms on Earth. The molar mass is appropriate for converting between the mass of a substance and the amount of a substance for bulk quantities.