AP Chemistry – 1 st Semester Final Exam Review
1. Ch3 HW#2 p124+ 73. Benzene contains only carbon and hydrogen and is 7.74% H by mass; the molar mass of benzene is 78.1 g/mol. Determine the empirical and molecular formulas of benzene.
2. Ch3 HW#4 p125+ 80. Give the balanced equation for each of the following chemical reactions.
a. Glucose (C
6
H
12
O
6
) reacts with oxygen gas to produce gaseous carbon dioxide and water vapor. b. Solid iron (III) sulfide reacts with gaseous hydrogen chloride to form solid iron (III) chloride and hydrogen sulfide gas.
3. Ch3 HW#6 p127 100. Mercury and Bromine will react with each other to produce mercury(II) bromide
Hg(l) + Br
2
(l) HgBr
2
(s) a. What mass of HgBr
2
can be produced from the reaction of 10.0g Hg and 9.00g Br
2
?
What mass of which reagent is left unreacted? b. What mass of HgBr
2
can be produced from the reaction of 5.00 mL mercury (density = 13.6 g/ml) and 5.00 mL bromine (density = 3.10 g/ml)?
4. Ch4 HW#1 p180+ 15.Calculate the molarity of each of these solutions. a. A 5.623g sample of NaHCO
3
is dissolved in enough water to make 250 ml of solution.
5. Ch4 HW#2 p181 23. Describe how you would prepare 2.00 L of each of the following solutions. a. 0.250M NaOH from solid NaOH b. 0.250M NaOH from 1.00M NaOH stock solution
6. Ch4 HW#4 p182 43. A 100.0-mL aliquot of 0.200 M aqueous potassium hydroxide is mixed with 100.0 mL of 0.200 M aqueous magnesium nitrate. Magnesium hydroxide precipitates out.
a. Write a balanced chemical equation for any reaction that occurs. b. What mass of precipitate is produced? c. Calculate the concentration of each ion remaining in solution after precipitation is complete.
7. Ch4 HW#7 p182+ 57. Assign oxidation states for all atoms in each of the following compounds. a. KMnO
4 b. NiO
2 e. P
4
O
6 f. Fe
3
O
4 h. SF
4 i. CO
8. Ch4 HW#8 p183 65. Balance the following oxidation-reductions reactions that occur in basic solutions. a. Al(s) + MnO
4
(aq) MnO
2
(s) + Al(OH)
4
(aq)
9. Ch4 Rev p180+ 62a. Specify if Cu
(s)
+ 2Ag +
(aq)
 2Ag
(s)
+ Cu +2
(aq)
is an oxidation-reduction reaction, and identify the oxidizing agent, the reducing agent, the substance being oxidized, and the substance being reduced.
10. Ch5 HW#1 p232+ 30. A balloon is filled to a volume of 7.00x10
2 mL at a temperature of 20.0°C. The balloon is then cooled at a constant pressure to a temperature of 1.00x10
2 K. What is the final volume of the balloon?
11. Ch5 HW#2 p233 38. What volume is occupied by 2.0 g of He at 25˚C and a pressure of 775 mm Hg?
12. Ch5 HW#3 p233+ 49. Calculate the volume of O
2
, at STP, required for the complete combustion of 125 g octane (C
8
H
18
) to CO
2
and H
2
O.
13. Ch5 HW#4 p234 55. Hydrogen cyanide is prepared commercially by the reaction of methane, CH
4
(g), ammonia,
NH
3
(g), and oxygen, O
2
(g), at high temperature. The other product is gaseous water. a. Write a chemical equation for the reaction. b. What volume of HCN(g) can be obtained from 20 L CH
4
(g), 20 L NH
3
(g), and 20 L O
2
(g)? The volumes are all measured at the same temperature and pressure.
14. Ch5 HW#4 p234 57. A gas consisting of only carbon and hydrogen has an empirical formula of CH
2
. The gas has a density of 1.65 g/L at 27 o C and 734 torr. Determine the molar mass and molecular formula of the gas.
15. Ch5 HW#5 p234+ 63. Consider the flasks diagrammed what are the partial pressures of H
2
and N
2
after the stopcock between the two flasks is opened?
(Assume the final volume is 3 L)
What is the final pressure in torr?

16. Ch5 HW#5 p234+ 65. The partial pressure of CH
4
(g) is 0.175 atm and that of O
2
(g) is 0.250 atm in a mixture of the two gasses. What is the mole fraction of each gas in the mixture?
17. Ch5 HW#7 p237+ 79. Consider three identical flasks filled with different gases.
Flask A: CO at 760 torr and 0 o C Flask B: N
2
at 250 torr and 0 o C Flask C: H
2
at 100 torr and 0 o C a. In which flask will the molecules have the greatest average kinetic energy? b. In which flask will the molecules have the greatest average velocity?
18. Ch5 HW#7 p237+ 81. The effusion rate of an unknown gas is measured and found to be 31.50mL/min.
Under identical experiment conditions, the effusion rate of O
2
is found to be 30.50mL/min.
If the choices are CH
4
, CO,NO,CO
2
, and NO
2
what is the identity of the unknown gas?
19. Ch6 HW#1 p283 26. Consider the mixture of air and gasoline vapor in a cylinder with a piston. The original volume is 40.0 cm 3 . If the combustion of this mixture releases 950. J of energy, to what volume will the gases expand against a constant pressure of 650 torr if all the energy of combustion is conserved into work to push the piston.
20. Ch6 HW#4 p283 29. The equation for the fermentation of glucose to alcohol and carbon dioxide is
C
6
H
12
O
6
(aq) → 2C
2
H
5
OH(aq) + 2CO
2
(g)
The enthalpy change for the reaction is -67kJ. Is the reaction exothermic or endothermic?
Is energy, in the form of heat, absorbed or evolved as the reaction occurs?
21. Ch6 HW#4 p283 34. The overall reaction in commercial heat packs can be represented as
4Fe(s) + 3O
2
(g) → 2Fe
2
O
3
(s) ΔH = -1652kJ
How much heat is released when: d. 10.0 g Fe and 2.00 g O
2
are reacted?
22. Ch6 HW#6 p284 47.Consider the dissolution of CaCl
2
: CaCl
2(s)
→ Ca 2+
(aq)
+ 2Cl -
(aq)
ΔH = -81.5 kJ
An 11.0g sample of CaCl
2
is dissolved in 125 g of water, with both substances at 25.0˚C. Calculate the final temperature of the solution assuming no heat lost to the surroundings and assuming the solution has a specific heat capacity of 4.18 J/˚C·g
23. Ch6 HW#7 p284 55. Given the following data:
2O
3
(g) → 3O
2
(g)
O
2
(g) → 2O(g)
ΔH = -427 kJ
ΔH = +495 kJ calculate ΔH for the reaction
NO(g) + O(g) → NO
2
(g)
NO(g) + O
3
(g) → NO
2
(g) + O
2
(g) ΔH = -199 kJ
24. Ch6 HW#8 p285 61. Use the values of ΔH f o in Appendix 4 to the calculate ΔH o for the following reactions. a. 2NH
3
(g) + 3O
2
(g) + 2CH
4
(g) → 2HCN(g) + 6H
2
O(g)
25. Ch7 HW#1 p341 43. It takes 7.21 x 10 -19 J of energy to remove an electron from an iron atom.
What is the maximum wavelength of light that can do this?
26. Ch7 HW#1 p341 45. Calculate the de Broglie wavelength for: a. A proton with a velocity of the 2.7x10
8 m/s.
27. Ch7 HW#2 p340 49. Caculate the wavelength of light emitted when the following transition occurs in the hydrogen atom. a. n=3 →n=2
28. Ch7 HW#6 p343 83. Arrange the following groups of atoms in order of increasing size: a. Be, Mg, Ca
29. Ch7 HW#6 p343 85. Arrange the atoms in Exercise 83 in order of increasing first ionization energy.
30. Ch7 HW#6 p343 87. Which atom or ion has the smallest radius? c. O + , O, O - d. S, Cl, Kr
31. Ch7 HW#7 p340+ 121. The successive ionization energies for an unknown element are:
I
1
= 896kJ/mol I
2
= 1752 kJ/mol I
3
= 14,807 kJ/mol I
4
= 17948 kJ/mol
To which family in the periodic table does the unknown element most likely belong?
32. Ch7 HW#7 p340+ 122. An unknown element is a nonmetal and has a valence electron configuration of ns 2 np 4 a) How many valence electrons does this element have? b) What are some possible identities for this element? c) What is the formula of the compound this element would form with potassium? d) Would this element have a larger or smaller radius than barium? e) Would this element have a greater or smaller ionization energy than fluorine?
33. Ch8 HW#1 p405 1. Explain the electronegativity trends across a row and down a column of the periodic table.
Compare these trends with those of ionization energies and atomic radii. How are they related?
34. Ch8 HW#1 p405 21. Without using Fig. 8.3, predict which bond in each of the following groups will be the most polar. a. C---F, Si---F, Ge---F
35. Ch8 HW#4 p408 64. Write Lewis structures that obey the octet rule for each of the following molecules and ions.
(the first atom listed is the central atom.) a. POCI
3
, SO
4
2 , PO
4
3 , CIO
4
-
FRQs: Stoiciometric Lab Analysis Chemical Reaction with Oxidation Numbers Stoiciometric Gas Reaction
Molar Enthalpy and Calorimetery Bonding and Intermolecular Forces