Ch.3 - Chemical ReactionsWorksheetSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds
Sections
Empirical Formula
Molecular Formula
Combustion Analysis
Combustion Apparatus
Polyatomic Ions
Naming Ionic Compounds
Writing Ionic Compounds
Naming Ionic Hydrates
Naming Acids
Naming Molecular Compounds
Balancing Chemical Equations
Stoichiometry
Limiting Reagent
Percent Yield
Mass Percent
Functional Groups in Chemistry
Additional Practice
Molecular Models
Ionic and Covalent Compounds
Metal Alloys
Additional Guides
Theoretical Yield (IGNORE)
Balancing Chemical Equations Worksheet (IGNORE)
Limiting Reactant (IGNORE)

The empirical formula gives the relative number of atoms. 

Empirical Formula

Concept #1: Empirical Formula

Example #1: Determine the empirical formula of a compound that is 68.40% chromium and 31.60% oxygen.

Practice: A compound that contains only carbon, hydrogen, and oxygen is composed of 48.64% C and 43.2% O by mass. What is the empirical formula of this compound?

Practice: Elemental analysis of a sample of an ionic compound showed 2.82 g of Na, 4.35 g of Cl, and 7.83 g of O. What is the empirical formula of the compound?

Practice: A compound composed of carbon, hydrogen, and chlorine contains 4.19 x 1023 hydrogen atoms. If 9.00 g of the compound also contains 55.0% chlorine by mass, what is the empirical formula?