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Chapter 10 Chemical Quantities

10.2

The Mole

Copyright © 2008 by Pearson Education, Inc.Publishing as Benjamin Cummings

Section 10.1The Mole: A Measurement of Matter

OBJECTIVES:Describe methods of measuring the amount of something.

Section 10.1The Mole: A Measurement of Matter

OBJECTIVES:Define Avogadro’s number as it relates to a mole of a substance.

Section 10.1The Mole: A Measurement of Matter

OBJECTIVES:Distinguish between the atomic mass of an element and its molar mass.

Section 10.1The Mole: A Measurement of Matter

OBJECTIVES:Describe how the mass of a mole of a compound is calculated.

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Collection Terms

A collection term states a specific number of items.

• 1 dozen donuts = 12 donuts

• 1 ream of paper = 500 sheets

• 1 case = 24 cans

Copyright © 2008 by Pearson Education, Inc. Publishing as Benjamin Cummings

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A mole (mol) is a collection that contains

• The same number of particles as there are carbon atoms in 12.01 g of carbon.

• 6.022 x 1023 atoms of an element (Avogadro’s number).

1 mol C = 6.022 x 1023 C atoms

1 mol CO2 = 6.022 x 1023 CO2 molecules

1 mol NaCl = 6.022 x 1023 NaCl formula units

A Mole of Particles

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Samples of One Mole Quantities

Table 6.1

Copyright © 2008 by Pearson Education, Inc. Publishing as Benjamin Cummings

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Using Avogadro’s NumberAvogadro’s number• Converts moles of a substance to

the number of particles. • Converts particles of a substance to

moles.

Copyright © 2008 by Pearson Education, Inc.Publishing as Benjamin Cummings

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Subscripts and Moles

The subscripts in a formula state• The relationship of atoms in the formula.• The moles of each element in 1 mol of compound.

Glucose

C6H12O6

In 1 molecule: 6 atoms C 12 atoms H 6 atoms O

In 1 mol: 6 mol C 12 mol H 6 mol O

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Subscripts State Atoms and Moles

1 mol C9H8O4 = 9 mol C 8 mol H 4 mol O

Copyright © 2008 by Pearson Education, Inc. Publishing as Benjamin Cummings

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Learning Check

A. How many moles O are in 0.150 mol aspirin C9H8O4?

B. How many O atoms are in 0.150 mol aspirin C9H8O4?

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Solution

A. How many mol O are in 0.150 mol aspirin C9H8O4?

0.150 mol C9H8O4 x 4 mol O = 0.600 mol O

1 mol C9H8O4

subscript factor

B. How many O atoms are in 0.150 mol aspirin C9H8O4?

0.150 mol C9H8O4 x 4 mol O x 6.022 x 1023 O atoms

1 mol C9H8O4 1 mol O subscript Avogadro’s

factor Number= 3.61 x 1023 O atoms

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Learning Check

How many O atoms are in 0.150 mol aspirin C9H8O4?

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Solution

How many O atoms are in 0.150 mol aspirin C9H8O4?

0.150 mol C9H8O4 x 4 mol O x 6.022 x 1023 O atoms

1 mol C9H8O4 1 mol O

subscript Avogadro’s

factor number

= 3.61 x 1023 O atoms