Final answer:
To determine the molecular formula of a compound with a given mass percent composition, we need to calculate the empirical formula first. We can then determine the molecular formula by multiplying the empirical formula by a whole number factor.
Step-by-step explanation:
To determine the molecular formula of a compound with a given mass percent composition, we need to calculate the empirical formula first. From the given information, we know that the compound is composed of carbon (C), hydrogen (H), and/or oxygen (O), with a mass percent of 74.8% carbon.
Assuming a 100 g sample, this means we have 74.8 g carbon. We can calculate the mass of hydrogen and oxygen by subtracting the mass of carbon from 100 g. Let's say we have x g hydrogen and y g oxygen.
To find the empirical formula, we need to convert the masses of each element to their respective moles. We can then divide the number of moles of each element by the smallest number of moles calculated. This will give us the simplest ratio. From there, we can determine the empirical formula.