To find the scaling factor, you need to divide the molar mass of the molecular formula by the molar mass of the empirical formula. In this case, the molecular formula has a molar mass of 150.0 g/mol and the empirical formula has a molar mass of 30.03 g/mol. The calculation is as follows: Scaling factor = 150.0 g/mol / 30.03 g/mol = 4.994. Since the hint indicates that the answer should be a whole number, we round 4.994 up to 5. Therefore, the scaling factor is 5, which indicates how many times the empirical formula must be multiplied to obtain the molecular formula.