The Mole

1
Chapter 9

• The Mole
• Calculations Using Molar Mass

2
Collection Terms

• 1 trio 3 singers
• 1 six-pack Cola 6 cans Cola drink
• 1 dozen donuts 12 donuts
• 1 gross of pencils 144 pencils

3
A Mole of Particles

• Contains 6.02 x 1023 particles
• 1 mole C 6.02 x 1023 C atoms
• 1 mole H2O 6.02 x 1023 H2O molecules
• 1 mole NaCl 6.02 x 1023 Na ions and
• 6.02 x 1023 Cl ions

4
More Examples of Moles

• Moles of elements
• 1 mole Mg 6.02 x 1023 Mg atoms
• 1 mole Au 6.02 x 1023 Au atoms
• Moles of compounds
• 1 mole NH3 6.02 x 1023 NH3 molecules
• 1 mole C9H8O4 6.02 x 1023 aspirin molecules

5
Avogadro's Number

• 6.02 x 1023 particles
• 1 mole
• or
• 1 mole
• 6.02 x 1023 particles

6
Learning Check M1

• Suppose we invented a new collection unit called
  a mep. One mep contains 8 objects.
• A. How many paper clips in 1 mep?
• 1) 1 2) 4 3) 8
• B. How many oranges in 2.0 meps?
• 1) 4 2) 8 3) 16
• C. How many meps contain 40 gummy bears?
• 1) 5 2) 10 3) 20

7
Solution M1

• Suppose we invented a new collection unit called
  a mep. One mep contains 8 objects.
• A. How many paper clips in 1 mep?
• 3) 8
• B. How many oranges in 2.0 meps?
• 3) 16
• C. How many meps contain 40 gummy bears?
• 1) 5

8
Learning Check M2

• 1. Number of atoms in 0.500 mole of Al
• 1) 500 Al atoms
• 2) 6.02 x 1023 Al atoms
• 3) 3.01 x 1023 Al atoms
• 2.Number of moles of S in 1.8 x 1024
• S atoms
• 1) 1.0 mole S atoms
• 2) 3.0 mole S atoms
• 3) 1.1 x 1048 mole S atoms

9
Solution M2

• 1. Number of atoms in 0.500 mol of Al
• 3) 3.01 x 1023 Al atoms
• 0.500 mol Al x 6.02 x 1023 Al atoms
• 1 mol Al
• 2. Number of moles of S if a sample of S contains
  4.50 x 1024 S atoms
• 2) 3.0 mole S atoms
• 4.50 x 1024 S atoms x 1 mol S
  
• 6.02 x 1023 S atoms

10
Molar Mass

• Number of grams in 1 mole
• Equal to the numerical value of the atomic mass
• 1 mole of C atoms 12.0 g
• 1 mole of Mg atoms 24.3 g
• 1 mole of Cu atoms 63.5 g

11
Learning Check M3

• Give the molar mass to 0.1 g
• A. 1 mole of Br atoms ________
• B. 1 mole of Sn atoms ________

12
Solution M3

• Give the molar mass to 0.1 g
• A. 1 mole of Br atoms 79.9 g/mole
• B. 1 mole of Sn atoms 118.7 g/mole

13
Molar Mass of Compounds

• Mass in grams of 1 mole equal numerically to the
  sum of the atomic masses
• 1 mole of CaCl2 111.1 g/mole
• 1 mole Ca x 40.1 g/mole
• 2 moles Cl x 35.5 g/mole
• 1 mole of N2O4 74.0 g/mole
• 2 moles N x 14.0 g/mole
• 4 moles O x 16.0 g/mole

14
Learning Check M4

• A. 1 mole of K2O ______g
• B. 1 mole of antacid Al(OH)3 ______g

15
Solution M4

• A. 1 mole of K2O 94.2 g
• 2 K x 39.1 g/mole 1 O x 16.0 g/mole
• B. 1 mole of antacid Al(OH)3 78.0 g
• 1 Al x 27.0 g/mole 3 O x 16.0 g/mole
• 3 x 1.0

16
Learning Check M5

• Prozac, C17H18F3NO, is a widely used
  antidepressant that inhibits the uptake of
  serotonin by the brain. It has a molar mass of
• 1) 40.0 g/mole
• 2) 262 g/mole
• 3) 309 g/mole

17
Solution M5

• Prozac, C17H18F3NO, is a widely used
  antidepressant that inhibits the uptake of
  serotonin by the brain. It has a molar mass of
• 3) 309 g/mole
• 17C (12.0) 18H (1.0) 3F (19.0) 1N (14.0)
  1 O (16.0)

18
Learning Check M6

• What is the percent carbon in C5H8NO4 (MSG
  monosodium glutamate), a compound used to flavor
  foods and tenderize meats?
• 1) 8.22 C
• 2) 24.3 C
• 3) 41.1 C

19
Solution M6

• Molar mass 146.0 g/mole
• total g C x 100
• total g compound
• 60.0 g C x 100 41.1 C
• 146.0 g MSG

20
Molar Mass Factors for CH4

• Methane CH4 known as natural gas is used in gas
  cook tops and gas heaters. Express the molar
  mass of methane in the form of conversion
  factors.
• Molar mass of CH4 16.0 g
• 16.0 g CH4 and 1 mole CH4
• 1 mole CH4 16.0 g CH4

21
Learning Check M7

• Acetic acid CH3COOH is the acid in vinegar . It
  has a molar mass of 60.0 g/mole.
• 1 mole of acetic acid ____________
• 1 mole acetic acid or g
  acetic acid g acetic acid 1 mole
  acetic acid

22
Solution M7

• Acetic acid CH3COOH is the acid in vinegar . It
  has a molar mass of 60.0 g/mole.
• 1 mole of acetic acid 60.0 g
• 1 mole acetic acid or 60.0 g acetic
  acid 60.0 g acetic acid 1 mole acetic
  acid

23
Calculations with Molar Mass

• molar mass
• Grams Moles

24
Moles and Grams

• Aluminum is often used for the structure of
  light-weight bicycle frames. How many grams of
  Al are in 3.00 moles of Al?
• 3.00 moles Al ? g Al

25

• 1. Molar mass of Al
• 1 mole Al 27.0 g Al
• 2. Conversion factors for Al
• 27.0g Al or 1 mol Al
• 1 mol Al 27.0 g Al
• 3. Setup
• 3.00 moles Al x 27.0 g Al
• 1 mole Al
• Answer 81.0 g Al

26
Learning Check M9

• The artificial sweetener aspartame
  (Nutri-Sweet) formula C14H18N2O5 is used to
  sweeten diet foods, coffee and soft drinks. How
  many moles of aspartame are present in 225 g of
  aspartame?

27
Solution M9

• 1. Molar mass of Aspartame C14H18N2O5
• (14 x 12.0) (18 x 1.01) (2 x 14.0) (5 x
  16.0) 294 g/mole
• 2. Setup
• 225 g aspartame x 1 mole aspartame
• 294 g aspartame
• 0.765 mole aspartame