The elemental mass percent composition of ascorbic acid (vitamin C) is 40.92% C, 4.58% H, and 54.50% O. Determine the empirical formula of ascorbic acid.

Verified step by step guidance

1. Assume you have 100 grams of ascorbic acid. This allows you to directly convert the percentage of each element to grams: 40.92 g of C, 4.58 g of H, and 54.50 g of O.
2. Convert the mass of each element to moles by dividing by their respective molar masses: \( \text{Molar mass of C} = 12.01 \, \text{g/mol} \), \( \text{Molar mass of H} = 1.01 \, \text{g/mol} \), \( \text{Molar mass of O} = 16.00 \, \text{g/mol} \).
3. Calculate the moles of each element: \( \text{moles of C} = \frac{40.92}{12.01} \), \( \text{moles of H} = \frac{4.58}{1.01} \), \( \text{moles of O} = \frac{54.50}{16.00} \).
4. Determine the simplest whole number ratio of moles of each element by dividing each by the smallest number of moles calculated in the previous step.
5. If necessary, multiply the ratios by a common factor to obtain whole numbers for each element, which will give you the empirical formula of ascorbic acid.

Key Concepts

Mass Percent Composition

Mass percent composition refers to the percentage by mass of each element in a compound. It is calculated by dividing the mass of each element in one mole of the compound by the total molar mass of the compound, then multiplying by 100. This information is crucial for determining the relative amounts of each element present in a compound, which is essential for deriving its empirical formula.

Empirical Formula

The empirical formula of a compound represents the simplest whole-number ratio of the elements present in that compound. To determine the empirical formula, the mass percent composition is converted into moles for each element, and then the mole ratios are simplified to the smallest whole numbers. This formula provides insight into the basic composition of the compound without indicating the actual number of atoms in a molecule.

Mole Concept

The mole concept is a fundamental principle in chemistry that relates the mass of a substance to the number of particles it contains. One mole of any substance contains Avogadro's number (approximately 6.022 x 10^23) of entities, whether they are atoms, molecules, or ions. Understanding this concept is essential for converting mass percent compositions into moles, which is a necessary step in calculating the empirical formula.