The Mole
At this point in the course, students are now able to use the periodic table, write chemical formulas, name compounds, and balance chemical equations. The next important skill is understanding and using the mole. Moles are a measurement of the amount of atoms, particles, or molecules in a substance. Molar measurements are often very large numbers, such as Avagadro's number of 6.02 x1023. This means that students will also need to be comfortable performing calculations using scientific notation.
The Mole - Powerpoint Lecture
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Purpose: This is a brief Powerpoint lecture that guides students through the use of scientific notation, Avagadro's number, the use of mole as a measurement of amount, and some sample molar conversions including empirical and molecular formulas.
Essential Concepts: Moles, scientific notation, Avagadro's number, empirical formula, molecular formula.
The Mole - Student Notes Outline
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This is a fill-in-the-blank style notes outline for students to complete as you complete the accompanying Powerpoint lecture. Each slide has a set of questions, fill-in-the-blanks, or tables that students fill in based on the information given. This is a good aid for students who struggle with taking notes freehand.
Essential Concepts: Moles, scientific notation, Avagadro's number, empirical formula, molecular formula.
Scientific Notation and the Mole
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Purpose: The number of particles in a mole of any substance, Avagadro's number, is so large that it is hard for students to understand and visualize. This worksheet compares other measurements, such as the mass of the Earth as students practice writing large measurements in scientific notation and perform simple calculations using these measurements.
Essential Concepts: Moles, scientific notation, Avagadro's number.
Molar Mass
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Purpose: Molar mass, also known as formula mass, is the amount of mass of any substance that contains exactly one mole (6.02x1023) of particles. Before students can begin learning how to use molar conversions, they need to be able to accurately calculate the molar mass of any given compound or element. This worksheet provides examples of how to do this, and some practice problems for students to try on their own.
Essential Concepts: Moles, molar mass, formula mass.
Percent Composition
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Purpose: The percent composition of a compound is the percent, by mass, of each individual element within the compound. This worksheet is a good application of molar mass, as students will calculate the mass of the individual atoms of familiar compounds, such as baking soda.
Essential concepts: Molar mass, percent composition.
Single Step Molar Conversions
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Purpose: Moles are an incredibly useful unit of measurement in chemistry, because they allow you to convert between measurements of mass, amount of atoms, and volume. This worksheet has students use a "Mole Map" to practice converting between moles and grams, moles and liters (of a gas), and moles and particles.
Essential Concepts: Moles, molar conversions, conversion factor, formula mass, molar mass.
Two-Step Molar Conversions
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Purpose: Moles are often an “intermediate” unit used to convert between two more commonly used measurements, such as volume or mass. This can be accomplished the same way as single conversions, just with an extra step. This worksheet will give students guided practice in converting between particles and grams, grams and liters, and liters and particles.
Essential Concepts: Moles, molar conversions, conversion factor, formula mass, molar mass.
Empirical Formula
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Purpose: When a chemist is studying an unknown substance, it is possible to do a chemical analysis determining the percent composition of each element that makes up the substance. This percent composition can then be used to find the actual empirical formula, or the simplest possible ratio of elements of the compound. This worksheet instructs students how to use percent composition to calculate the empirical formula of an unknown compound.
Essential concepts: Moles, molar mass, mole ratio, percent composition, empirical formula.
Molecular Formula
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Purpose: Many compounds do not naturally exist as their simplest empirical formula. Glucose, for example, has an empirical formula of CH2O. However, it actually exists as a multiple of this ratio, called the molecular formula. Int his worksheet, students will calculate molecular formula by comparing the molar mass of the empirical formula to that of the actual compound.
Essential Concepts: Empirical formula, molecular formula, molar mass.
Moles and Molecular Formulas Study Guide
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Purpose: Once the instruction for the unit is completed, students can complete this study guide to aid in their preparation for a written test. The study guide is divided into two sections: vocabulary and short answer questions. The vocabulary words can be found scattered throughout the different instructional worksheets from this unit. The short answer questions are conceptual and meant to see if the students are able to apply what they've learned in the unit.
