Skip to main content
Ch.3 - Chemical Reactions and Reaction Stoichiometry
Brown - Chemistry: The Central Science 15th Edition
Brown15th EditionChemistry: The Central ScienceISBN: 9780137542970Not the one you use?Change textbook
All textbooksBrown 15th EditionCh.3 - Chemical Reactions and Reaction StoichiometryProblem 46c
Chapter 3, Problem 46c

Determine the empirical formula of each of the following compounds if a sample contains c. 87.5% N and 12.5% H by mass.

Verified step by step guidance
1
Convert the percentage of each element to grams, assuming you have a 100 g sample. This means you have 87.5 g of N and 12.5 g of H.
Convert the mass of each element to moles by dividing by their respective molar masses: N (14.01 g/mol) and H (1.01 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 get whole numbers for each element in the compound.
Write the empirical formula using the whole number mole ratios as subscripts for each element.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
1m
Was this helpful?

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 percentage composition of each element by mass, allowing chemists to understand the basic composition of a substance without detailing the actual number of atoms in a molecule.
Recommended video:
Guided course
02:26
Empirical vs Molecular Formula

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 the element in the compound by the total mass of the compound and multiplying by 100. This concept is crucial for determining the empirical formula, as it provides the necessary data to find the ratio of elements.

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. This concept is essential for converting mass percentages into moles, which are then used to derive the empirical formula.
Recommended video:
Guided course
01:25
Mole Concept
Related Practice
Textbook Question

Determine the empirical formula of each of the following compounds if a sample contains b. 5.28 g Sn and 3.37 g F;

3
views
Textbook Question

Give the empirical formula of each of the following compounds if a sample contains b.11.66 g iron and 5.01 g oxygen

3
views
Textbook Question

Give the empirical formula of each of the following compounds if a sample contains a.0.0130 mol C, 0.0390 mol H, and 0.0065 mol O

2
views
Textbook Question

Determine the empirical formulas of the compounds with the following compositions by mass: a. 55.3% K, 14.6% P, and 30.1% O

3
views
Textbook Question

A compound whose empirical formula is XF3 consists of 65% F by mass. What is the atomic mass of X?

2720
views
Textbook Question

Determine the empirical formulas of the compounds with the following compositions by mass: c. 62.1% C, 5.21% H, 12.1% N, and the remainder O

2
views