Final answer:
The molecular formula for the molecule with an empirical formula of C2H40 and a molar mass of 176.21 g/mol is C8H160.
Step-by-step explanation:
To determine the molecular formula, we first need to calculate the empirical formula mass, which is the sum of the atomic masses of the elements in the empirical formula. In this case, the empirical formula is C2H40, so the empirical formula mass is calculated as follows:
C: 2 * 12.01 amu = 24.02 amu
H: 4 * 1.01 amu = 4.04 amu
O: 1 * 16.00 amu = 16.00 amu
The empirical formula mass is therefore 44.06 amu/formula unit. Next, we calculate the empirical formula mass as a ratio of the molar mass (176.21 g/mol) to the empirical formula mass (44.06 amu/formula unit):
(176.21 g/mol) / (44.06 amu/formula unit) ≈ 4
This indicates that the molecular formula is 4 times the empirical formula. Therefore, the molecular formula of the molecule is 4 * C2H40 = C8H160.