1. Atomic Structure and Properties
AP Chemistry Unit 1
Lundquist

2. Moles and Molar Mass
Unit 1.1

3. The mole No a furry burrowing animal
A representative amount of a substance
A word which represents a number (like 1 doz = 12, or 1 ream = 500)
Used to count atoms, particles, ions, etc.

4. The mole 1 mole is 6.022 x 1023 Use it like any conversion
1 mole = x 1023
Use it like any conversion
Example 1
0.5 mol is how many molecules of O2?
How many moles is 1.81 x 1024 atoms of gold?

5. Atom Inventory Subscript Coefficient
Apply to what is DIRECTLY in front of them
Coefficient
Apply to the WHOLE molecule
So 1 mol of water (1 H2O), contains:
2 mol H
1 mol O
Therefore, 6 mol of water (6 H2O), contains:
12 mol H
6 mol O

6. The mole 1 mole is 6.022 x 1023 Use it like any conversion
1 mole = x 1023
Use it like any conversion
Example 1
How many atoms of each element are in moles of Sulfuric acid (H2SO4)?

7. The forking Mole!
Whenever you are lost in a problem, always (ALWAYS) find the number of moles.
Moles will safe your life
Moles. Moles. MOLES!!!!

8. History of the mole
Dalton was the first to make a table of relative masses
Used hydrogen
H doesn’t bond with metals
Berzelius used oxygen as it bonds with most other elements
Issues arose with understanding of isotopes
16O was used as the standard
IUPAC developed the model used today in 1960, based off 12C
Accounts for 98.9% of all carbons

9. Carbon-12 12C has a mass of EXACTLY 12 amu
12g of 12C contains x1023 atoms of C
the masses on the periodic table are the mass of 1 mole of that element

10. Molar Mass the mass of 1 mole of a compound

11. Molar Mass Example 2 How much would 2.00mol CH4 weight?
How many moles is in 9.00g H2O?

12. Molar Mass
Example 3
A cup of Starbucks coffee contains 36.0g of sugar, house hold sugar is sucrose (C12H22O11). How many moles of sugar in a cup of coffee? How many molecules?

13. Do p. 17 for number 11, what would the units of molar mass be?

14. How we know the mass of atoms now

15. How we know the mass of atoms now
Mass in g
Simple ratio
Relative mass
Mass in g

16. Average Atomic Mass Number of protons (+) charge in the nucleus
Number of e- if neutral
Average atomic mass
Isotopes (heavier/lighter atoms)
Weighted average

17. Isotopes Only protons and neutrons contribute to the mass of an atom
Atoms of the same element all have the same number of protons
Atoms of the same element can have different number of neutrons

18. Average Atomic Mass
𝐴𝑣𝑒𝑟𝑎𝑔𝑒.𝐴𝑡𝑜𝑚𝑖𝑐.𝑀𝑎𝑠𝑠=( 𝑚 1 % 1 )+( 𝑚 2 % 2 )+( 𝑚 3 % 3 )...
Mass of isotope
Percent abundance as a decimal

19. Example 4
When a sample of natural copper is vaporized and injected into a mass spectrometer, the results shown in the figure are obtained. Use these data to calculate the average mass of natural copper. (The mass values for 63Cu and 65Cu are amu and amu, respectively.)

20. Example 5
A sample of argon contains 2 isotopes 39Ar and 40Ar, given the average atomic mass of argon what is the percent abundance of each isotope?

21. Do p. 18 Show work using the right side of the page

22. On AP Classroom do the unit 1.1 quiz
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23. Elemental analysis
Unit 1.2

24. Percent Composition You are 70% water The earth is 50% oxygen
The sun is 75% hydrogen

25. Simple percent composition
Example 6
If a sample is 5.0 g and is found to contain 3.75g C, and the rest is H, what percent is C? What percent is H?
If a sample is 5.0 g and is found to contain 3.75g C, and the rest is H, what percent is C? What percent is H?
% 𝐶 = 3.75𝑔𝐶 5.0𝑔 𝐶 𝑥 𝐻 𝑦 ×100=75 % 𝐶 % 𝐻 = 5.0𝑔−3.75𝑔𝐶 5.0𝑔 𝐶 𝑥 𝐻 𝑦 ×100= 1.25𝑔𝐶 5.0𝑔 𝐶 𝑥 𝐻 𝑦 ×100=25 % 𝐻

26. Percent Composition 𝐴 2 𝐵 3 % 𝐴 = 2𝐴 2𝐴+3𝐵 ×100 Example 7
What is the present by mass of each element in ethanol (C2H5OH)?
𝐴 2 𝐵 % 𝐴 = 2𝐴 2𝐴+3𝐵 ×100

27. Percent Composition 𝐴 2 𝐵 3 % 𝐴 = 2𝐴 2𝐴+3𝐵 ×100 Example 8
What mass of carbon can be captured from 10g of ethanol (C2H5OH)?
𝐴 2 𝐵 % 𝐴 = 2𝐴 2𝐴+3𝐵 ×100

28. Do p. 19

29. Chemical Formulas Molecular Formulas Empirical formulas
Actual number of each element present
Used for covalent compounds
Simplest ratio of one element to another
Used for ionic compounds

30. Molecular to empirical
Example 9
Write the empirical formula for each compound:
H2O
C2H2
As2O10

31. Chemical Formulas Converting from empirical formulas to molecular formulas
Since the formula is reduced by a whole number the mass is also reduced by a whole number
Determine the whole number and you can find the molecular formula
4 P + 10 O
4(39.97) + 10 (16)
319.88g/mol
2 P + 5 O
2(39.97) + 5 (16)
g/mol
𝑬𝒎𝒑𝒊𝒓𝒊𝒄𝒂𝒍= 𝑨 𝒙 𝑩 𝒚 𝑴𝒐𝒍𝒆𝒄𝒍𝒖𝒍𝒂𝒓=( 𝑨 𝒙 𝑩 𝒚 )𝒏 𝒏= 𝑴 𝑴 𝒎𝒐𝒍𝒆𝒄𝒖𝒍𝒂𝒓 𝑴 𝑴 𝒆𝒎𝒑𝒊𝒓𝒊𝒄𝒂𝒍 𝑴𝒐𝒍𝒆𝒄𝒖𝒍𝒂𝒓= 𝑨 𝒏𝒙 𝑩 𝒏𝒚

32. Empirical to molecular
Example 10
A compound with the empirical formula of CH2O has a molar mass of 180g/mol, what is its molecular formula?

33. When in doubt, burn it.
Gravimetric / elemental analysis

34. The Poem By Mrs. Freeman Percent to mass Mass to mole Divide by small
Multiple till whole
This elemental analysis allows us to determine the formula units (empirical formula) of a substance

35. Find the empirical formula
Example 11
A white powder is analyzed and found to contain 43.64% P and 56.36% O by mass.

36. Find the molecular formula
Example 12
A white powder is analyzed and found to contain 43.64% P and 56.36% O by mass. (example 11)
The compound has a molar mass of g/mol. What are the compound’s empirical and molecular formulas?

37. Mixtures Mixtures Pure substances
Contain molecules, or formula units, of two or more types
Proportions can vary (if not desired these are referred to as impurities)
Elemental analysis can be used to determine the purity
Contain molecules, or formula units, of a single type

38. Hydrates
Ionic compounds (metals with a positive charge attached to nonmetals with a negative charge)
can surround water molecules in the air
Transition metals are colorful
Cu = blue/teal
Co = pink
CuSO4
Copper sulfate anhydride
CuSO4.H2O
Copper sulfate dihydrate

39. Copper (X) Chloride lab part 1
Blue means record!
Gently warm a crucible
Mass your warm crucible
Dehydrate ~1 g of CuxCly.ZH2O
Cool (5 mins)
Reheat your crucible
Write your name on a Dixie cup and mass it
wash your crucible with H2O, and collect in your Dixie cup
Sand/shine Al bar
Place Al bars in Dixie cups and store in fume hood
May take 3 times
Complete lab based take home quiz by end of week!

40. Do p. 20 use the right side of the page to show work and answers

41. On AP Classroom do the unit 1.2 quiz
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42. Atomic Structure
Unit 1.3

43. Copper (X) Chloride lab part 2
Decant liquid out of Dixie cup
Scrap Al bar into Dixie cup
Rinse with water
Rinse with ethanol
Place Dixie cups under heat lamp
Place Al bars in collection beaker

45. Coulomb’s Law The long distance relationship rule
The force of attraction between two objects is proportional to their charges, and inverse to the distance between them
The long distance relationship rule

46. Review with your table Question Word Bank
Describe the nature of interaction between protons and electrons in an atom.
Word bank
Attraction
Repulsion
Neutral
Positive
Negative
Charge
Distance
Nucleus
Force
Energy
Coulomb’s Law

47. Which will require more energy to separate?

48. Which will require more energy to separate?

49. How many e-?

50. How many p+?

51. Which of these e- Will be the easiest (require the least energy) to remove (ionize)? Why?

52. How does that compare with these. Which will be easiest to ionize
How does that compare with these? Which will be easiest to ionize? Rank them A B C

53. First ionization energy
Remove 1 e- in the gas phase of an element
𝑒𝑛𝑒𝑟𝑔𝑦+ 𝐴 𝑔 → 𝐴 𝑔 𝑒 −

54. Which has less energy?
𝑒𝑛𝑒𝑟𝑔𝑦+ 𝐴 𝑔 → 𝐴 𝑔 𝑒 −
𝐴 𝑔 1+
𝐴 𝑔

55. Why is this an endothermic (requires energy) process?
𝑒𝑛𝑒𝑟𝑔𝑦+ 𝐴 𝑔 → 𝐴 𝑔 𝑒 −
𝐴 𝑔 1+
𝐴 𝑔

56. The value of the first ionization energy is 1312 𝑘𝐽 𝑚𝑜𝑙
The value of the first ionization energy is 1312 𝑘𝐽 𝑚𝑜𝑙 . on the graph on the next page put a horizontal line to indicate the energy of each species
𝑒𝑛𝑒𝑟𝑔𝑦+ 𝐻 𝑔 → 𝐻 𝑔 𝑒 −

57. Why is it negative? What does the difference in the two lines represent?
𝑒𝑛𝑒𝑟𝑔𝑦+ 𝐻 𝑔 → 𝐻 𝑔 𝑒 −

58. How would you explain the difference in the 1st ionization energy of H with He?
Remember this analogy?
How does your explanation account for the relative charge on H and He the distance of electron(s) from the nucleus?

59. Draw the 1st ionization energy of H and He. PREDICT A VALUE FOR Li

60. 520

62. 496
738
789
1046
1297
1530

66. Shells Layers of electrons around the nucleus Energy levels
Based on distance from the nucleus

67. Bohr Models Show electrons in their shell
Shows nuclear charge and number of neutrons
Outer most shell is known as the valence shell

68. Copper (X) Chloride lab
Mass Dixie cup and Cu
Calculate mass of Cu
Complete lab based take home quiz by end of week!

69. Shape of Atoms

70. Do All electrons in the same energy level have the same energy??
To answer this we can look at photoelectric spectroscopy data

71. Photoelectric Spectroscopy Data

72. PES data What does the x-axis symbolize?
What’s the relationship between the 1st ionization energy of H (1312 𝑘𝐽 𝑚𝑜𝑙 ) and the PES data?

73. He is next How many e- does He have in its first shell?
Predict what the PES would look like if
The same amount of energy was needed to remove an electron
Different amounts of energy were required to remove an electron He

74. What it actually looks like

75. Li

76. What it actually looks like

79. That’s weird, what happens if we keep going?
The little blip grows.
How many electrons would you say are in that large blip for Ne?
How do all the “shells” relate to one another?

80. Orbitals & Subshells Subshells Electrons can be ANYWHERE
Probability distribution around the nucleus
Orbitals
Divisions of that distribution based on space and magnetism

82. Example 13
Write the complete ground electron configuration for each element Cl I

83. 1s2 2s2 2p6 3s2 3p6 4s1

84. 1s2 2s2 2p6 3s2 3p6 4s2

85. 1s2 2s2 2p6 3s2 3p6 4s2_____

86. Rules for Electron Configuration
Aufbau Principle
Lower energy levels fill first
Follow the periodic table and you will be fine

88. Noble gas notation Short cut
[previous noble gas] any other subshells & orbitals

89. Example 14
Write the noble gas configuration for each element Be U

90. Ions The Universe is lazy
Noble gasses have the least energy, thus are inert
Nonmetals will gain e- to be like noble gasses
More e- = more (-)
Metals will loose e- to be like noble gasses
Less e- = more (+)

91. Excited state

92. Do p. 21

93. Orbital Notation Diagram for showing the spin of an electron
Hund’s Rule
e- won’t double up unless they have to
Pauli’s Exclusion Principle
Two e- cannot spin in the same direction in the same place

94. Example 15
Draw the orbital diagram for the element Se and O

95. Magnetism Diamagnetic No unfilled subshells Paramagnetic
At least 1 unfilled subshell
Ferromagnetic
LOTS of unfilled subshells
Found in the middle of the d-block and f-block

96. On AP Classroom do the unit 1.3 quiz
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97. Periodic Trends
Unit 1.4
(Test SOON!)

98. Periodic Trends

99. EXPLAINATIONS Right to left Top to Bottom
Increased effective nuclear charge (Zeff)
Increased principle energy level (number of shells)

100. Atomic Radius Which would be smaller??
As nuclear charge increases there is more attraction for the nucleus so atoms get smaller

101. Atomic Radius
As you gain shells you move further from the nucleus

102. Atomic Radius Increases from top to bottom
Decreases from left to right

103. First ionization energy
REMEMBER Coulomb’s Law
Smaller elements
Larger elements

104. First ionization energy
Decreases from top to bottom
Increases from left to right

105. Electronegativity Ability of an atom to attract an electron
Scale from 0-4
Same-ish as electron affinity

106. Ionic Radius Cations (+) Anions (-) Positive ions Have LESS e-
Same charge in nucleus
Pull e- closer in
Group 1 – 13 (all metals)
Negative ions
Have MORE e-
More repulsion from more e-
Pushes e- further out
Groups 15-18

108. Ionic Radius

109. Free Response Practice! Do p. 22

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