How do you determine the empirical formula of a compound?

Determining the empirical formula of a compound involves finding the simplest whole-number ratio of the different elements present in that compound. This process typically begins by measuring the mass of each element in the compound, allowing you to calculate the number of moles of each element by dividing the mass by its relative atomic mass.

Once you have the number of moles for each element, you can express these values as a ratio. The next step is to simplify this ratio to the smallest whole numbers, which gives you the empirical formula. Thus, the method encapsulated in the choice is accurate because it describes the essential process to arrive at the empirical formula reliably, showing how to transition from mass to moles and then to a reduced ratio.

In the context of the other options, they don't encompass the correct process for finding the empirical formula, focusing on less relevant aspects or methods that don't yield the correct result. For example, simply multiplying the number of atoms doesn't account for the differing atomic masses of the elements involved. Additionally, using the highest number of moles does not provide a systematic approach to obtaining a ratio, and combining elements in equal volumes relates to stoichiometry and gas laws rather than the empirical formula calculation itself.