1. The Mole and Chemical Composition
Chemistry 2
Chapter 7
The Mole and Chemical Composition

2. Chapter 7 Table of Contents
The Mole and Chemical Composition
Chapter 7
Table of Contents
Section 1 Avogadro’s Number and Molar Conversions
Section 2 Relative Atomic Mass and Chemical Formulas
Section 3 Formulas and Percentage Composition
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3. Section 1 Avogadro’s Number and Molar Conversions
Chapter 7
Objectives
Identify the mole as the unit used to count particles, whether atoms, ions, or molecules.
Use Avogadro’s number to convert between amount in moles and number of particles.
Solve problems converting between mass, amount in moles, and number of particles using Avogadro’s number and molar mass.
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4. Chapter 7 Number of particles Moles [mol] Mass [g]
Section 1 Avogadro’s Number and Molar Conversions
Chapter 7
Moles [mol]
Mass [g]
Number of
particles
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5. Avogadro’s Number and the Mole
Section 1 Avogadro’s Number and Molar Conversions
Chapter 7
Avogadro’s Number and the Mole
A mole is the number of atoms in exactly 12 grams of carbon-12.
The number of particles in a mole is called Avogadro’s Number. Avogadro’s number is × 1023 units/mole.
Molar mass is the mass in gram of one mole of a substance.
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6. Converting Between Mass, Amount, and Number of Particles
Section 1 Avogadro’s Number and Molar Conversions
Chapter 7
Converting Between Mass, Amount, and Number of Particles
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7. Converting Moles to Number of Particles
Section 1 Avogadro’s Number and Molar Conversions
Chapter 7
Converting Moles to Number of Particles
Example Problems
1. Find the number of molecules in 4.3 mol of tungsten.
2. How many moles equivalent to 7.95 x 10^24 copper(II) chloride.
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8. Chapter 7 Solve the following problems
Section 1 Avogadro’s Number and Molar Conversions
Chapter 7
Solve the following problems
1. How many particles are present in each of the following?
a x 10^-6 mol of nickel(II)selenide.
b mol selenium tetrabromide.
2. How many moles equivalent to each of the following?
a. 6.9
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