Final answer:
To determine the empirical formula of a compound, convert the mass of each element to moles, divide by the smallest mole value to get a ratio, and adjust to smallest whole numbers. The molecular formula is derived by multiplying the empirical formula by an integer based on the compound's molar mass.
Step-by-step explanation:
The process to determine the empirical formula of a compound from its percent composition involves several steps. To begin, assume you are dealing with a 100 g sample, which allows direct conversion of percentages into grams. Then, calculate the number of moles of each element using their respective molar masses. The empirical formula is derived by finding the simplest whole-number ratio of the moles of each constituent element.
- Convert the mass of each element to moles using the molar mass.
- Divide the number of moles of each element by the smallest number of moles to obtain a tentative ratio.
- If necessary, multiply all ratios by an integer to achieve the empirical formula with the smallest whole-number subscripts.
To convert an empirical formula to a molecular formula, the molar mass of the compound is essential. It is obtained using analytical techniques such as mass spectrometry. The molecular formula is the integer multiple of the empirical formula that matches the true molar mass of the compound.