Final answer:
The experiment 5 is about determining the empirical formula of magnesium oxide by converting the element masses of a compound to moles to find the simplest whole-number ratio of atoms.
Step-by-step explanation:
The subject of experiment 5 is the determination of the empirical formula of magnesium oxide. Determining empirical formulas is a fundamental procedure in chemistry that involves measuring the masses of a compound's elements and converting those masses into moles. By doing this, chemists can then find the simplest whole-number ratio of atoms within a compound, which results in the empirical formula. This process is important for understanding the composition of compounds and is distinct from determining other properties such as the boiling point, solubility, or density.
For example, if a compound contains 1.71 g of carbon (C) and 0.287 g of hydrogen (H), we would convert these masses to moles using their respective molar masses and then calculate the whole-number ratio of moles of C to H. This ratio would give us the empirical formula. The empirical formula for a compound can be the same as its molecular formula if the compound exists as simple molecules, such as water (H₂O) or carbon dioxide (CO₂).
The empirical formula mass tells us the sum of the masses of the elements represented in the empirical formula, and it is useful for further calculations in stoichiometry and to derive molecular formulas.