AP Chemistry
Big Idea 1
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Chapters in textbook: 1-3, 6.8-6.9, 7
Pages in review book: 1-44, 93-112, 113-130
Topics
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Empirical and molecular formulas
Limiting reactants
Electron configuration and orbital notation
Periodic trends (general and complex)
Practice problems in review book: pg 39-41(all MC and the 1 FR), pg 106 (MC 3-5), pg 125-126 (all MC and FR #1)
Example review problems:
1. What is the empirical formula of a compound containing 68.4% Cr and 31.6% Oxygen? The molar mass of this
compound is 304 g/mol. What is the molecular formula for this compound?
2. 255g of octane and 1510g of oxygen gas are present at the beginning of the reaction that goes to completion
and forms carbon dioxide and water, 2C8H18 + 25O2  16CO2 + 18H2O.
a. What is the limiting reactant?
b. How many grams of water are formed?
c. How many grams of excess reactant is consumed?
d. How much excess reactant is left over?
3. Write the electron configuration and orbital notation for Ga.
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4. Write examples of a violation of Hund’s rule, violation of Pauli Exclusion Principle, and an element in an excited
state.
5. General Periodic Trends
a. Why does the atomic radius of atoms decrease as you move left to right on the periodic table? Bottom
to top?
b. Explain why ionization energy increases as you move across and up the periodic table.
6. Complex Periodic Trends
a. Which ion has a larger radius, Mg+2 or O-2? Why?
b. Why does boron have a slightly lower first ionization energy than beryllium?
c. Determine the element from the ionization energies (kj/mol) listed below:
1st
2nd
3rd
4th
5th
580
1,815
2,740
11,600
14,800
a) Na
b) Mg
c) Al
d) Si
e) P
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Big Idea 2
Chapters in textbook: 8-10
Pages in review book: 131-188
Topics
 Lewis dot structures
 Combine gas law
 Octet rule + exceptions
 Ideal gas law
 Resonance
 Partial pressure
 Shapes!!
 Graham’s law of effussion
 Polarity
Practice problems in review book: pg 143-145 (all MC and all FR), pg 160-162 (all MC and all FR), pg 181-184 (all MC
and all FR)
Example review problems:
1. Use simple structure and bonding models to justify the following statements:
a. Explain why atoms of second row elements such as N and O cannot have expanded octets, but those of
third row elements such as P and S can.
b. Discuss the differences in length of bond, strength of bond, and the type of bonds in the following
molecules: CO2, H2S, and NO3.
2. For each of the following:
a. draw the molecular geometry of the molecule;
b. state the molecular geometry of the molecule;
c. determine if the molecule is polar or non-polar;
d. include bond angle(s).
CO2
ClF3
SF4
CCl4
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3.
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A student collected a sample of hydrogen gas by the displacement of water as shown by
the diagram above. The relevant data are given in the following table.
GAS SAMPLE DATA
Volume of sample
90.0 mL
Temperature
25 ºC
Atmospheric Pressure
745 mm Hg
Equilibrium Vapor Pressure of
H2O (25°C)
23.8 mm Hg
a. Calculate the number of moles of hydrogen gas collected.
b. Calculate the number of molecules of water vapor in the sample of gas.
c. Calculate the ratio of the average speed of the hydrogen molecules to the average speed of the water
vapor molecules in the sample.
d. Which of the two gases, H2 or H2O, deviates more from ideal behavior? Explain your answer.
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Big Idea 3
Chapters in textbook: 4, 13.1, 13.4, 16.5, 20
Pages in review book: 45-70, 223-238, 349-375
Topics
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Oxidation Reduction reactions
M1V1=M2V2
Titrations
Neutralization reactions
Solubility rules
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Balancing redox reactions
Voltaic cells
Cell Potentials
Free energy and redox
Electrolysis
Practice problems in review book: pg 64 (MC 1-2, 5-7 and FR #1), pg 368 (all MC and all FR)
Example review problems:
1. Answer the following questions about electrochemistry.
a. Several different electrochemical cells can be constructed using the materials shown below. Write the
balanced net-ionic equation for the reaction that occurs in the cell that would have the greatest positive
value of Ecello.
b. Calculate the standard cell potential, Ecello, for the reaction written in part a.
c. A cell is constructed based on the reaction in
part a above. Label the following on the picture
below:
i. metal used for the anode
ii. metal used for the cathode
iii. the amount and direction of electron
flow through the wire.
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d. How would the voltage of the cell be affected if the salt bridge was removed? Justify your answer.
e. Of the compounds, NaOH, CuS, and NaNO3, which one is appropriate to use in a salt bridge? Briefly
explain your answer, and for each of the other compounds, include a reason why it is not appropriate.
2. To solution 1 (2.00 L of 0.445 M HCl), you add 3.88 L of solution 2 (an unknown concentration of HCl). The
resulting solution is 0.974 M. Assuming the volumes are additive, calculate the molarity of solution 2.
3. Using solution 2 from above, if you add 250 mL of 1.0 M NaOH to 125 mL of solution 2, will the solution be
acidic, basic, or neutral? Justify your answers by showing all your work.
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Big Idea 6
Chapters in textbook: 15, 16, 17
Pages in review book: 261-328
Topics
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Equilibrium Constant
K vs. Q
Le Chatelier’s Principle
Strong vs. Weak A/B
Conjugate A/B
Ka x Kb = Kw = 1.0 x 10-14
pH= -log[H+]
pOH= -log[OH-]
pH + pOH = 14
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5% rule
Common Ion effect
Buffers
A/B titration
Equivalence point
Titration curve
Half equiv. point at pKa
pH= pKa + log ([base]/[acid])
Solubility product constant
Practice problems in review book: pg 271 (ALL MC and FR), pg 298 (ALL MC and FR), pg 321 (ALL MC and FR)
Example review problems:
Answer the following question:
1. What is the pH of a 0.75M solution of ammonia? (Kb=1.8 x 10-5)
2. What is the pH of a solution made by mixing 1.0L of 0.11M HCl with 3.0L of 0.080M NaF? (HF’s Ka=6.8 x 10-4)
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3. Calculate the molarity of an acetic acid solution if 34.57 mL of this solution are needed to neutralize 25.19
mL of 0.1025 M sodium hydroxide.
CH3COOH (aq) + NaOH (aq)
Na+(aq) + CH3COOH-(aq) + H2O (l)
4. For CeF3 the Ksp= 8 x 10-16.
a. Calculate the molar solubility in water.
b. Calculate the molar solubility in 0.2M CeCl3.
c. Calculate the molar solubility in 0.2M NaF.
AP Chemistry
Answers:
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1. What is the pH of a 0.75M solution of ammonia? (Kb=1.8 x 10-5)
I
C
E
NH3 + H2O  NH4+ + OH0.75M
0
0
-X
+X
+X
0.75 – X
X
X
Kb=1.8 x 10-5= X2
0.75
-3
X= 3.67 x 10 M= [OH-]
pOH=-log(3.67 x 10-3M)
pOH=2.44
pH=14 – 2.44= 11.56
2. What is the pH of a solution made by mixing 1.0L of 0.11M HCl with 3.0L of 0.080M NaF? (HF’s Ka=6.8 x 10 -4)
HCl + NaF  HF + NaCl
H+ + F-  HF
Mol HCl= 1.0L x 0.11mol/L= 0.11 mol HCL
Mol NaF= 3.0L x 0.080mol/L= 0.24 mol NaF
**Strong acid will completely neutralize weak base
**buffer solution= weak A and weak B
weak base=0.13 mol Fweak acid=0.11 mol HF
pH= pKa + log ([base]/[acid])
pH=3.17 + log (0.13/0.11)= 3.24
3. Calculate the molarity of an acetic acid solution if 34.57 mL of this solution are needed to neutralize 25.19
mL of 0.1025 M sodium hydroxide.
Na+(aq) + CH3COOH-(aq) + H2O (l)
CH3COOH (aq) + NaOH (aq)
M1V1=M2V2
X(34.57 mL)= (0.1025M)(25.19 mL)
X= 0.747 M
4. For CeF3 the Ksp= 8 x 10-16.
a. Calculate the molar solubility in water.
I
C
E
CeF3 (s) Ce+3 + 3F?
0
0
-x
+x
+3x
?-x
x
x
I
C
E
b. Calculate the molar solubility in 0.2M CeCl3.
CeF3 (s) Ce+3 + 3FKsp=[ Ce+3][ F-]3
?
0.2M 0
8 x 10-16= (0.2)(3x3)
-x
+x
+3x
x= 5.0 x 10-6 M
?-x
0.2+x x
Ksp=[ Ce+3][ F-]3
8 x 10-16= x(3x)3
x= 7.0 x 10-5 M
c. Calculate the molar solubility in 0.2M NaF.
I
C
E
CeF3 (s) Ce+3 + 3F?
0
0.2M
-x
+x
+3x
?-x
x
0.2+x
Ksp=[ Ce+3][ F-]3
8 x 10-16= (x)(0.2)3
x= 1.0 x 10-13 M