Final answer:
To find the molecular formula of the compound with a molar mass of 92.02 g/mol and a percent composition of 30.4% N and 69.6% O, we first find the empirical formula by converting the masses to moles and then determining the simplest whole number ratio. The empirical formula is NO₂, so the molecular formula is also NO₂.
Step-by-step explanation:
To determine the molecular formula of a compound, we need to know its molar mass and percent composition. In this case, the compound has a molar mass of 92.02 g/mol, with 30.4% nitrogen (N) and 69.6% oxygen (O). We can assume a 100 g sample of the compound, which means we have 30.4 g of N and 69.6 g of O. To find the empirical formula, we need to convert the masses to moles by dividing by the atomic masses of N and O (14.01 g/mol and 16.00 g/mol, respectively).
The number of moles of N is 30.4 g / 14.01 g/mol = 2.17 mol.
The number of moles of O is 69.6 g / 16.00 g/mol = 4.35 mol.
To find the simplest whole number ratio of N to O, we divide each by the smallest number of moles, which is 2.17 mol. The ratio is approximately 2:4, which simplifies to 1:2. So, the empirical formula is NO₂. To find the molecular formula, we need to determine the actual number of atoms in the compound. Since the empirical formula tells us that there is one N atom and two O atoms, the molecular formula of this compound is NO₂.