1. Launch: 12/15
 Grab your binder and immediately take a seat!
 Place HW (Review Worksheet #1), binder paper, and a
pen/pencil on your desk.
Review Objective #2:
Tonight’s HW: Finish Review Worksheet #2

2. Launch 12/15
4. Which of the following is a balanced equation for
the combustion of ethanol (C2H5OH)?
a. C2H5OH + 3O2  CO2 + 2H2O
b. C2H5OH + 3O2  2CO2 + 3H2O
c. C2H5OH + O2  2CO2 + 3H2O
d. C2H5OH + 2O2  3CO2 + 2H2O

3. Launch 12/15
__C2H2 + __H2  __CH4
5. When the equation above is completely balanced,
the coefficient for H2 would be
a. 1
b. 2
c. 3
d. 4

4. Launch 12/15
4. Which of the following is a balanced equation for
the combustion of ethanol (C2H5OH)?
a. C2H5OH + 3O2  CO2 + 2H2O
b. C2H5OH + 3O2  2CO2 + 3H2O
c. C2H5OH + O2  2CO2 + 3H2O
d. C2H5OH + 2O2  3CO2 + 2H2O

5. Launch 12/15
__C2H2 + __H2  __CH4
5. When the equation above is completely balanced,
the coefficient for H2 would be
a. 1
b. 2
c. 3
d. 4

6. Announcements
 Unit #5 Exam on Thursday
 2 days to review
 Ask questions!
 No copying HW or classwork!
 Make-up work is due on Wednesday
 Binder check this week

7. Exam Information
 30 multiple-choice questions
 Balancing equations (6 questions = 20%)
 The mole (9 questions = 30%)
 Conversions (15 questions = 50%)
 gram  mole (6 questions)
 gram  atoms (3 questions)
 gram  gram (6 questions)
 3 free response

8. Review:
The Mole
Mr. Heffner
12/15/09

9. What’s a mole?

10. What’s a mole?
 A mole is…
 a unit of measurement
 the number of atoms in 12g of carbon-12
 6.02 X1023 atoms
 Avogadro’s # ..or particles, or molecules

11. What’s molar mass?
 Molar mass is…
 the sum of the atomic masses in a molecule
 a.k.a “molecular mass”
C2H2
Molar mass = mass of C + mass of C + mass of H + mass of H
= 2X(mass of C) + 2X(mass of H)
= 2X(12.01) + 2X(1.01)
= 24.02 + 2.02
= 26.04 g/mol Units!

12. Conversions
? grams 6.02 X 1023 atoms
1 mole 1 mole
? moles
Grams ? moles Moles Atoms
1 mole 1 mole
? grams 6.02 X 1023 atoms

13. Conversions
 There is a 3-step process for conversions:
1. Write down the starting information and look at the ending
information.
2. Using the “Heart of Chemistry”, pick the correct conversion
number “How many…”
factor(s).
3. Cancel like terms and do the math!

14. Example #1
How many moles of H2O are there in 9.01 grams of H2O?
 Step #1: Write down the starting information and look at the
ending information.
9.01 grams

15. Example #1
How many moles of H2O are there in 9.01 grams of H2O?
 Step #2: Using the “Heart of Chemistry”, pick the correct
conversion factor(s).
9.01 grams X

16. Example #1
How many moles of H2O are there in 9.01 grams of H2O?
 Step #2: Using the “Heart of Chemistry”, pick the correct
conversion factor(s).
? grams 6.02 X 1023 atoms
1 mole 1 mole
? moles
Grams ? moles Moles Atoms
Start 1 mole 1 mole
? grams 6.02 X 1023 atoms
End
Molar mass

17. Example #1
How many moles of H2O are there in 9.01 grams of H2O?
 Step #2: Using the “Heart of Chemistry”, pick the correct
conversion factor(s).
1 mole
9.01 grams X =
18.02 grams

18. Example #1
How many moles of H2O are there in 9.01 grams of H2O?
 Step #3: Cancel like terms and do the math!
1 mole 9 X 1 mole
9.01 grams X =
18.02 grams 18
= .5 moles
units!

19. Example #2
How many atoms are there in 1.5 moles of CO2?
 Step #1: Write down the starting information and look at the
ending information.
1.5 moles

20. Example #2
How many atoms are there in 1.5 moles of CO2?
 Step #2: Using the “Heart of Chemistry”, pick the correct
conversion factor(s).
1.5 moles

21. Example #2
How many atoms are there in 1.5 moles of CO2?
 Step #2: Using the “Heart of Chemistry”, pick the correct
conversion factor(s).
? grams 6.02 X 1023 atoms
1 mole 1 mole
? moles
Grams ? moles Moles Atoms
1 mole 1 mole End
? grams 6.02 X 1023 atoms
Start

22. Example #2
How many atoms are there in 1.5 moles of CO2?
 Step #2: Using the “Heart of Chemistry”, pick the correct
conversion factor(s).
6.02 X 1023 atoms
1.5 moles X =
1 mole

23. Example #2
How many atoms are there in 1.5 moles of CO2?
 Step #3: Cancel like terms and do the math!
Ignore
6.02 X 1023 atoms 1.5 X 6 X 1023 atoms
1.5 moles X =
1 mole 1
= 9 X 1023 atoms

24. Example #3
How many grams of CH4 are there in 12.04 X 1023 molecules?
 Step #1: Write down the starting information and look at the
ending information.
12.04 X 1023 molecules

25. Example #3
How many grams of CH4 are there in 12.04 X 1023 molecules?
 Step #2: Using the “Heart of Chemistry”, pick the correct
conversion factor(s).
12.04 X 1023 molecules X =

26. Example #3
How many grams of CH4 are there in 12.04 X 1023 molecules?
 Step #2: Using the “Heart of Chemistry”, pick the correct
conversion factor(s).
? grams 6.02 X 1023 atoms
1 mole 1 mole
? moles
Grams ? moles Moles Atoms
End 1 mole 1 mole Start
? grams 6.02 X 1023 atoms

27. Example #3
How many grams of CH4 are there in 12.04 X 1023 molecules?
 Step #2: Using the “Heart of Chemistry”, pick the correct
conversion factor(s).
1 mol 16.05 g
12.04 X 1023 molecules X X
1 mol
=
6.02 X 10 23 molecules

28. Example #3
How many grams of CH4 are there in 12.04 X 1023 molecules?
 Step #3: Cancel like terms and do the math!
1 mol 16.05 g
12.04 X 1023 molecules X X
1 mol
=
6.02 X 10 23 molecules
12 X 1 X 16 g
=
6X1
32 g = 2 X 16 g =

29. Conversion Rotations
 Directions:
 Pick a problem and fill in the blanks
 Solve showing all work
 When finished, Mr. Heffner will come around to stamp
your work
 Rules:
 If you pick it, solve it
 Only one card at a time
 Show your work!
 Work together

30. Exit Slip
1. What is the molar mass of Al(OH)3?
a. 43.99 g/mol
b. 78.01 g/mol
c. 300.03 g/mol
d. 303.00 g/mol

31. Exit Slip
2. How many moles of N2 are there in 28.02g of N2?
a. 1 moles
b. 2 mole
c. .5 moles
d. 28.02 moles

32. Exit Slip
3. Choose the answer below that shows how to calculate:
“How many atoms are there in 2 moles of O2?”
32.00 grams
a. 16 moles X
1 mole
1 mole
b. 2 moles X 16.00 grams
1 atoms
c. 2 moles X 6.02 X 1023 moles
6.02 X 1023 atoms
d. 2 moles X
1 mole

33. Exit Slip
4. Which of the following correctly shows how to convert
64.00g of O2 to atoms?
6.02 X 1023 atoms
a. 32.00g X
32.00g
1 mole
b. 64.00g X 32.00 g
1 mole 6.02 X 1023 atoms
c. 64.00g X 32.00 g X 1 mole
1 mole 1 atoms
d. 64.00 g X X
6.02 X 10 23 g
32.00 moles

34. Exit Slip
5. How many grams does 12.04 X 1023 molecules of
H2O weigh?
a. 9.01g
b. 18.02g
c. 27.03g
d. 36.04g

35. Homework
 Finish practice questions worksheet