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Ch.3 - Chemical Reactions and Reaction Stoichiometry
Chapter 3, Problem 48c

Determine the empirical formulas of the compounds with the following compositions by mass: (c) 60.0% C, 4.4% H, and the remainder O

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Identify the mass percentages of each element: 60.0% C, 4.4% H, and the remainder O. Calculate the percentage of O by subtracting the sum of the percentages of C and H from 100%.
Assume a 100 g sample of the compound, which means you have 60.0 g of C, 4.4 g of H, and the remainder in grams of O.
Convert the masses of each element to moles by dividing by their respective atomic masses: C (12.01 g/mol), H (1.008 g/mol), and O (16.00 g/mol).
Determine the mole ratio of the elements by dividing each element's mole value by the smallest number of moles calculated in the previous step.
If necessary, multiply the mole ratios by a whole number to obtain the smallest whole number ratio for the empirical formula.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Empirical Formula

The empirical formula of a compound represents the simplest whole-number ratio of the elements present in that compound. It is derived from the mass percentages of each element, which are converted to moles and then simplified to the smallest integer ratio. This formula provides essential information about the composition of the compound without indicating the actual number of atoms in a molecule.
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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 10²³) of entities, whether they are atoms, molecules, or ions. This concept is crucial for converting mass percentages into moles, which is necessary for determining the empirical formula.
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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 a sample by the total mass of the sample and multiplying by 100. Understanding mass percent composition is essential for converting the given percentages into moles, which is the first step in finding the empirical formula of a compound.
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