1. Semester 2
The Mole
(Ch 3.3 and )

2. Warm up #1 What is a unit and why are they useful?
Why use something like a “dozen eggs” “a ream of paper” a “cord of wood” or a “mole of atoms” to talk about amounts?
Continue working on “Intro to Mole worksheet” in your classwork section.

3. Not talking about these kind of moles…

4. Or these…

5. Measuring Matter We live in a quantitative world… How much? How many?
How much do you make?
How old are you?
How long is this class?
How many questions are on the final exam?
How much? How many?
We measure by COUNT, MASS, and/or VOLUME.

6. Specific units = specific number
1 pair of shoes = 2 shoes
12 cupcakes =1 dozen cupcakes
1 reem of paper = 500 sheets
Each of these could be used as a conversion factor
If there are 800 students at LACHSA, how many dozen are there? Calculate it!
MOLES is a unit like these…it represents a certain number!!

7. Review: Scientific Notation
Scientific Notation—great for very large or very small numbers
Ex 1: Hope Diamond has ,000,000,000,000,000,000,000 atoms
Ex 2: 1 Carbon atom of the Hope Diamond has a mass of g
4.6 x 1023 atoms = Hope Diamond atoms (not 45 x 1022)
2 x grams = carbon atom mass
4.6 and 2 are the coefficients of the number
The 10 to the raised power represents the number of decimal places

8. Convert these to Sci. Notation
3,000,000,000
4500
438,000
0.056
3x109
4.5x103
2.3x10-5
4.38x105
2.45x10-3
5.6x10-2

9. Calculations to practice
Learn how to use your calculator!
Calculations to practice
(2.3 x 103)(8.2 x 104) =
(7.34 x 10-5)(8.221 x 10-2) =
9 x 106 ÷ 4.00 x 103 =
6.23 x x 105 =
Think on this…do you need to write down EVERY single number the calculator gives you???
Sig figs!
Answer to x 108
x 10-6
x 103
x 105

10. SI Units (Systeme Internationale)
Meter for length
Use a meterstick to measure
Kilogram for mass (1 kg = 2.2 lbs)
Weight is NOT the same thing as mass!
Use a scale to measure
Kelvin for temperature
K = oC + 273
0 K = absolute zero
Use a thermometer to measure
oC is another option, but not Fahrenheit (in the metric system)
Second for time
Use a stopwatch to measure
Mole for the amount of substance
We will talk about mole next chapter
Liter for volume
Use a graduated cylinder to measure
joule or calorie for energy
We don’t discuss this much in this class…

11. What is a Conversion Factor?
Conversion factors
Values can often be expressed in more than one form
$1 = 4 quarters = 10 dimes = 20 nickels = 100 pennies
1 meter = 100cm = 1000mm = 0.001km
equal values can be shown as a ratio equal to 1; such ratios are called conversion factors…
conversion factors are useful for solving problems in which given measurements must be expressed in some other unit.

12. Dimensional Analysis
Dimensional Analysis: a way to problem solve/calculate that uses conversion factors to solve problems.
Calculate how many seconds old you are?
If you can run the 100 m dash in seconds, how many kilometers per hour is that?

13. Dimensional Analysis Ex: Convert 1,000 kilometers into millimeters.
Ex: A boat is to be three hundred cubits long, fifty cubits wide and thirty cubits high. How big is that in feet?
HINT: 1 cubit = 45 cm; 1 foot = 30 cm

14. MOLES: measures amount of matter
1 mole = x 1023 of anything
Moles are handy when there are large quantities of matter.
What if you needed to count the number of grains of sand in 10 grams???
1 mole of apples = 602,200,000,000,000,000,000,000 apples
Thank goodness for scientific notation! 
1 mole of $$ = $6.022 x 1023
1 mole of cheerios = x 1023 cheerios

15. A mole is 6.02 x 1023 of anything!
A mole of basketballs would just about fit into a ball bag the size of the Earth! So just how big is a mole?
Draw a 1 inch square box on your paper:
When the teacher says “go” put as many dots in that box as you can in 30 seconds.
Now, count the dots. (A highlighter or differently-colored pen may be useful.) x2, What is your dot making rate in dots/minute? _____________
Working at this rate, how many dots could you make in an hour? _____________________
If a student can make 303 dots per minute, it will take 3.78 x 1015 years to make a mole of dots!
Even if 25 students in the class worked at this rate, it would take the class x 1014 years, making dots 24-7, to make a mole of dots!

16. More on moles… 6.022x1023 is referred to as Avogadro’s Number
1 mole of Fe atoms = x 1023 atoms
1 mole CO2 molecules= x1023 molecules
1 mol NaCl molecules= x1023 molecules
Why the different units for Fe vs. CO2 vs NaCl??

17. One more thing 1 mole =‘s Molar mass= atomic mass = g/mol
1 mole of carbon = 12.0 grams
1 mole of Fe = g
1 mole of S = 32.1 g/mol
Look at a periodic table, where are these numbers coming from?
for our purposes, we will round to 1 decimal place for each atomic mass
Atomic mass= mass of 1 mole of the atom
Molar mass= atomic mass = g/mol
Unit can be g or g/mol

18. So just to recap… What is the mass of 1 mole of any element?
it’s atomic mass
Where do you find it?
Periodic table…(decimal value)
What is its unit of measurement?
Grams or grams/mol
What is the molar mass of carbon?
What is the molar mass of sodium?
What is the molar mass of lithium?
The mass of the periodic table is the mass of 1 mole!= molar mass

19. What is the Mass of 1 Mole of a COMPOUND???
To find the mass of 1 mole of a compound, you must know the formula of the compound.
Molar masses of chemical compounds = the sums of the molar masses of all the atoms in one molecule of that compound.
Ex: calculate the molar mass of 1 mole of carbon dioxide.

20. Molar mass of a compound
Calculate the mass of 1 mole of Sodium Chloride (salt)
Gotta know the formula: NaCl
Na = 23.0 g x 1 atom in the compound = 23.0 g
Cl = 35.5 g x 1 atom in the compound = g
Total = = 58.5 g
The molar mass of NaCl = 58.5 g
1 mole of NaCl = 58.5 g

21. Example problems: Calculate the molar mass of water.
18.0 g/mol
Calculate the mass of 1 mole of PCl3.
137.5 g/mol
Calculate the molar mass of Zn(NO3)2.
189.4 g/mol
4. How many moles in 1.8x1028 atoms of gold?

23. Molar Road Map Mole Mass g # of Particles Pg 84 molar mass 1mol _
6.022x1023 atoms
Mass g
# of
Particles
(atoms, molecules)
1 mole
molar mass
6.022x1023 atoms
1mole
Use to convert between mole and mass and amount of particles

24. Molar Road Map Mole Mass g # of Particles Pg 84 molar mass (g) = 1 mol
(atoms, molecules)
1 mol = 6.022x1023
particles
Use to convert between mole and mass and amount of particles

25. Converting b/w Moles & Molecules
When we convert moles to: molecules, atoms, formula units, etc, we use the following conversion factors:

26. Ex: moles to particles = 1.20x1024 molecules 2.00 moles x
How many molecules are in 2.00 moles of sucrose?
2.00 moles x
= 1.20x1024
molecules

27. Ex: molecules to moles
How many moles are in 2.33 x 1024 molecules of water?
How many atoms are in 2.95 moles of Au?
3.87 moles
1.77 x 1024

28. Molar Road Map Mole Mass g # of Particles Pg 84 molar mass (g) = 1 mol
(atoms, molecules)
1 mol = 6.022x1023
particles
Use to convert between mole and mass and amount of particles

29. Converting b/w Moles & Grams (the most common calculation!)
We use molar mass as a conversion factor:
Ex: grams to moles
Calculate the number of moles in 75.0 g dinitrogen trioxide.

30. Ex: grams to moles
Calculate the number of moles in 75.0 g dinitrogen trioxide.
Find molar mass of N2O3
Use conversation factor
14.01x x3 = 76.02g/mole
1 mole
76.02g
75.0g x
= .986mol N2O2

31. Mole  Mass You need 3.0 moles of NaCl for a lab experiment.
The molar mass can be used to convert between mass and moles. Need to be able to go both ways…from moles to mass or mass to moles.
You need 3.0 moles of NaCl for a lab experiment.
How are you going to measure out 3.0 moles? Can’t do it on a scale…
You need to convert from moles to grams.
In order to convert, you need to know the mass of 1 mole of NaCl
Now solve…

32. 1s2 2s2 2. 1s2 2s2 2p3 3. 1s2 2s2 2p6 3s2 3p6 4s2 3d8 (or 1s2 2s2 2p6 3s2 3p6 3d8 4s2)
4. 1s2 5. 1s2 2s2 2p6 3s2 3p4

33. Ex: moles to grams
Calculate the mass, in g, of moles of sodium chloride.
Calculate the number of moles in 75.0 g of nitrogen gas.
14.36 g
NaCl = 57.45g/mol

34. Review: Moles of …. How much is ONE mole of Zinc Water (H2O) NaCl
Chromium
Magnesium
Sodium Bicarbonate
Hydrogen peroxide
carbon

35. The mole is a unit Mole song Boseman:
WMjo

36. Molar Road Map Mole Mass g # of Particles Pg 84 molar mass (g) = 1 mol
(atoms, molecules)
1 mol = 6.022x1023
particles
Use to convert between mole and mass and amount of particles

37. Problems to Practice How many molecules are in 1.14 moles of SO3?
(6.87 x 1023 atoms)
Calculate the mass in grams of 2.50 moles of Iron (II) Hydroxide. (Who remembers how to write this formula???)
(225 grams)
Fe(OH)₂

38. Problems to Practice
3. If you have 7.31 grams of CuSO4, how many moles is this?
( moles)
4. How many moles are in 4.65 x molecules of NO2
Is this a 1 step or 2 step problem???
(0.772 moles)

39. Molar Road Map Mole Mass g # of Particles Pg 84 molar mass 1mol _
6.022x1023 atoms
Mass g
# of
Particles
(atoms, molecules)
1 mole
molar mass
6.022x1023 atoms
1mole
Use to convert between mole and mass and amount of particles

40. Molar Road Map Mole Mass g # of Particles Pg 84 1 mol = molar mass
(atoms, molecules)
1 mol = 6.022x1023
Use to convert between mole and mass and amount of particles

41. Convert both ways (notes cont.)
1. Find the mass, in grams of 4.52 x molecules of C20H42?
(212 grams)
2. Find the number of atoms in 75.0 g of dinitrogen trioxide?
Molar mass = 76.0g/mol,
5.94x1023 atoms
3. How many grams are there in 2.80 x atoms of silicon?
Don’t forget your sig.figs!
4.65x28.1g = 131g
4. How many grams is 2.7 x 1023 molecules of Br2?
71.6 = 72g

42. Chalk activity

43. Warm up How many molecules are in 1.14 moles of SO3?
(6.87 x 1023 molecules)
Calculate the mass in grams of 2.50 moles of Iron (II) oxide.
179.8 g
How many grams are there in 2.80 x atoms of N2?
Don’t forget your sig.figs!
4.65x28.1g = 131g
Fe(OH)₂

44. Turn in warm ups and Mole worksheet!
Mole notes continued…

45. Notice the difference?
How many moles are there in 2.80 x 1024 atoms of silicon?
Don’t forget your sig.figs!
How many moles is 2.7 x 1023 molecules of Br2?
NOTICE: how we calculated for atoms when talking about an element and molecules when talking about a compound?
Can you calculate atoms for a compound? Could you calculate atoms of Br2?
YES, but that is not a single step problem…
…see next slide 

46. Number of atoms in a compound
Often multiple conversion factors are needed.
Like if you need to convert your age to seconds…
Go from years to months to days to hours to sec.
1. How many ATOMS of propane (a covlnt cmpd!!) are in 2.12 moles of propane (C3H8)?
Why can you NOT go straight from moles to atoms in this problem?
= 1.28x1024 C3H8 molecules
2.12 moles x
11 atoms per molecules
(1.28x1024) x 11 = 1.40 x1025 atoms

47. Number of atoms in a compound
How many ATOMS of Carbon are in moles of propane (C3H8)?
= 1.28x1024 C3H8 molecules
2.12 moles x
(1.28x1024) x 11 = 1.40 x1025 atoms
11 atoms per molecules
3/11 of atoms are C
3/11 (1.40 x1025 ) = C atoms

48. Molecules vs atoms How many molecules are in 1.14 moles of SO3?
(6.87 x 1023 molecules)
How many atoms are in 1.14 moles of SO3?
(2.75 x 1024 atoms)
5. How many atoms are in 1.09 x 1024 molecules of water?
6. How many atoms of hydrogen in 2,560 atoms of water?
7. How many atoms of hydrogen in 1.50 moles of water?

49. Molar mass What is the molar mass of 1 mole of lithium?
What is the molar mass of 1 mole of carbon dioxide?
What is molar mass of 35 grams of .5 mole of aluminum?
What is the molar mass of 10 moles of sodium that has a mass of 220 grams.

50. Use the mole map to solve:
How many moles are in g of H2O?
How many molecules are in moles of H2O?
How many atoms are in 1.09 x molecules of water?
What is the mass in grams of 7.23 x molecules of sucrose (C12H22O11)?

51. Warm ups #2 How many atoms of oxygen in 3.00 moles of carbon dioxide?
How many atoms of hydrogen in grams of H4CO

53. Chapter Goals: The Road Map
Volume (L)
The MOLE
Molecules, atoms,
formula units
Mass (g)

55. Molar Road Map Volume L Mole Mass g # of Particles Pg 84 1 mole 22.4 L
molar mass
1mole
Mole
1mol _
6.022x1023 atoms
Mass g
# of
Particles
(atoms, molecules)
1 mole
molar mass
6.022x1023 atoms
1mole

56. Molar Road Map Volume L Mole Mass g # of Particles Pg 84
1 mol = molar mass
Mass g
# of
Particles
(atoms, molecules)
1 mol = 6.022x1023

57. Mole-Volume Relationship
For gases, Avogadro (in 1811) proposed a significant relationship that stated that: equal volumes of gases at the same temperature and pressure contain equal numbers of particles.
Particle size varies for different gases but because particles are so spread out, they do not take up any greater amount of space.
Temp has an effect on volume
As temp. increases, volume increases
Pressure also has an effect on volume
As pressure increases, volume decreases
STP = Standard Temperature and Pressure
Temp = 0 degrees C & pressure = 1 atm

58. Converting b/t Moles & Volume
MOLAR VOLUME = 22.4 L/mol
(the volume of one mole of a gas)
One mole of ANY gas will expand to have a volume of 22.4 L at STP.
STP = Standard Temperature and Pressure
Standard Temp: 0 degrees C
Standard Pressure: 1 atm

59. Molar Volume Example The conversion factors (always):
1. How many moles of N2 are in 120 L of gas?
1mol
22.4L
120L x
= 5.36 mol N2
Can you then calculate the mass?

60. Molar Road Map Mass g Mole # of Particles Volume L Pg 84
(atoms, molecules)
1 mol = 6.022x1023
1 mol = molar mass
Volume L
22.4 L = 1 mole

61. More examples: mole and volume
2. What is the volume of 2.54 moles of methane gas?
56.9L
3. How many moles are in 6.00 L of H2 gas?
.268mol .3mol
4. How many grams are in 12 L of O2 gas?
17.1g= 17g
5. How many L of oxygen gas (at STP) are in 6.5 x molecules of oxygen gas?
242L = 240 L

62. Density= mass/ volume or D= g/L
6. The density of a gas at STP is g/L. What is the molar mass of the gas?
7. What gas is it?
neon
8. What is the density of 1.00 mole of helium gas?
g L
L mole
= 20.2 g/mol x
4.00 g/mol x 1mol/22.4 L = .179 g/L

63. Summary Follow the road map! Moles  L or L moles: molar volume
Moles  g or g  moles: molar mass

64. More Problems to Practice
0.6 moles of SO2 is produced when coal is burned. How many liters of gas at STP is this?
At STP, what volume does 1.25 moles of He occupy?
74.5 liters of CO2 at STP is contained in a flask. How many moles is this?
The density of a gas at STP is g/L. What is the molar mass of the gas?
What is the density of krypton gas at STP?

65. Molar Road Map: Title Moles (in the middle) Particles Mass Volume
In your Chemistry Notebook, classwork sections: Create your own molar road map including pictures and conversation factors. Be creative and use color. Include the following:
Title
Moles (in the middle)
Particles
Mass
Volume
Arrows between each unit (3 total)
Conversion factors between each unit (3 total)
A picture to represent each unit (4 total)
Color for emphasis

66. End day

67. Warm up At STP, what volume does 1.75 moles of He occupy?
What would be the volume of 8.00g of helium of STP?
What is the density of He at STP?
39.2L
44.8L
4.0g/mol x 1mol/22.4L = .179g/L

68. Calculate the number of moles in 9. 023 x 1023 molecules of NO2. (6
Calculate the number of moles in x molecules of NO2. (6.48 moles)
Calculate the volume of 2.30 moles of SO2 gas at STP. (51.5 L)
Find the molar mass of B2(SO3) g/mol

69. Percent Composition and Empirical FormulasCh

70. Percent composition: percent, by mass, of each element in a compound
Mass of element in 1 mol of compound
Molar mass of compound
% composition = x 100%
Ex: Find percent composition of Cu2S
Find molar mass of Cu2S
159.2g
127.1g Cu x 100% = 79.85% Cu
159.2g Cu2S
32.1g S x100% = 20.2 % S

71. Ex 2: dinitrogen pentoxide is 25. 9% nitrogen by mass
Ex 2: dinitrogen pentoxide is 25.9% nitrogen by mass. How many grams of nitrogen and oxygen are in a 125g sample of the compound?

72. Molecular Formula: total number of atoms of each element in one molecule of a compound Empirical Formula: smallest whole number ratio of the elements in a compound
Molecular or empirical?
C2H4 CH
H2O
H2O2
C6H12O6
C8H8
Na2SO4
If given the molecular formula, find the empirical formula.

73. Find Empirical Formula from %
Can go from % composition to empirical formula
change % to grams for each given (assume 100g sample)
change grams to mol (using molar mass from periodic table)
divide all by the lowest # mols (to get ratio)
write ratio as formula (if not whole #s, try multiplying all by 2)
Ex1: Quantitative analysis shows that a compound contains 32.38% sodium, 22.65% sulfur, and 44.99% oxygen. Find the empirical formula.
32.38 g Na, 22.65g S, 44.99g O
Divide each by 0.706
1.99 mol Na
1mol S
3.98 mol O
Na2SO4
32.38 g Na x 1mol/23.0g Na = mol Ns
22.65g S x 1mol/32.1g S = mol S
44.99g O x 1mol/16.0g O = mol O

74. Ex2:
A g sample of methyl benzoate, a compound used in the manufacture of perfumes, is found to contain g of carbon, g of hydrogen, and g of oxygen. What is the empirical formula of this substance?
Answer: C4H4O

75. Example 3

77. Ch 7.4
Pg 244 Practice: #1-3 Pg 249 section review # 1-2 (continue to 3-4 if finish early) 3-4 finish next class

78. Warm up

79. Warm up
What is the difference between an empirical and a molecular formula?
Give an example of each.

81. _______2. Which of the following is NOT an empirical formula?
A. HNO3 B. C4H4 C. CO2 D. NaCl

82. 24. Calculate the percent composition of each element in a compound that is made of 2.03 g of Mg and 1.25 g of N. (3 pts)
hint: remember % = (part/whole) × 100
25. Write the empirical formula for a compound that is 36.8% N and 63.2% O. (3 pts)
-step 1: change % to grams for each given -step 3: divide all by the lowest # mols
-step 2: change grams to mol -step 4: write whole number ratio as formula
26. Write the empirical formula for a compound that contains 65.45g of Carbon, 5.45g of Hydrogen, and g of Oxygen. (3 pts)
(need a clue? Use the steps 2, 3, and 4 from #25)

83. What you should learn in school.
Focus
Hard work
Problem solving
Critical thinking
Reaching high expectations
How to work with others
How to communicate
Perseverance
Overcome mistakes
Curiosity

85. Common Core Standards
HS-PS1-7. Use mathematical representations to support the claim that atoms, and therefore mass, are conserved during a chemical reaction.
HS-PS1-6. Refine the design of a chemical system by specifying a change in conditions that would produce increased amounts of products at equilibrium.
HS-PS1-5. Apply scientific principles and evidence to provide an explanation about the effects of changing the temperature or concentration of the reacting particles on the rate at which a reaction occurs.
HS-PS1-3. Plan and conduct an investigation to gather evidence to compare the structure of substances at the bulk scale to infer the strength of electrical forces between particles.

86. Common Core Standards
HS-PS1-7. Use mathematical representations to support the claim that atoms, and therefore mass, are conserved during a chemical reaction.
CA State Standards
D2. Investigate quantitative relationships in chemical reactions, and solve related problems;
D3. Demonstrate an understanding of the mole concept and its significance to the quantitative analysis of chemical reactions.

87. Common Core Standards
HS-PS1-6. Refine the design of a chemical system by specifying a change in conditions that would produce increased amounts of products at equilibrium.

88. Common Core Standards
HS-PS1-5. Apply scientific principles and evidence to provide an explanation about the effects of changing the temperature or concentration of the reacting particles on the rate at which a reaction occurs.

89. Common Core Standards
HS-PS1-3. Plan and conduct an investigation to gather evidence to compare the structure of substances at the bulk scale to infer the strength of electrical forces between particles.