Final answer:
The molecular formula is determined by calculating the mole ratios of elements based on their percent composition, finding the empirical formula, and then using the compound's molecular mass to convert the empirical formula into the molecular formula.
Step-by-step explanation:
Determining the Molecular Formula
To find the molecular formula of a compound, we need to use the percent composition and the molecular mass. First, we calculate the number of moles of each element in 100 grams of the compound. For carbon (C), which makes up 49.47% of the compound, we divide by its atomic mass (approximately 12.01 amu) to get the mole ratio for carbon. We repeat this process for hydrogen (H), nitrogen (N), and oxygen (O), using their respective percent compositions and atomic masses (approximately 1.01 amu for H, 14.01 amu for N, and 16.00 amu for O).
Once we have the mole ratios, we divide each by the smallest ratio to get a whole number ratio. This gives us the empirical formula of the compound. But the empirical formula only gives us the simplest ratio of elements in the compound, and we need the molecular formula, which requires the molecular mass. By dividing the molecular mass of the compound (194.2 amu) by the mass of the empirical formula unit, we get a factor that we multiply by the subscripts in the empirical formula to determine the molecular formula.
The above procedure with exact numbers and calculations will yield the molecular formula of the compound that corresponds to the percent composition given.