AP Chemistry by Satellite
Final Exam Part 2
The second part of the final consists of 29 multiple choice questions. All questions are weighted equally. Page 8 of this exam contains a periodic table and useful information. Additional information which may be required is included with the particular problem. The answer sheet is the last page. Remove it and complete the information listed. Write the letter indicating the most correct answer to each of the 29 questions, clearly and carefully using capital letters on the answer sheet. You need only turn in the answer sheet to this examination.
1. A solution of 5.00 g of unknown X dissolved in 20.0 g of benzene freezes at -4.52 ºC. Benzene normally freezes at 5.48 ºC and its kf is 5.12 ºC/m . What is the unknown X?
A) para-dichlorobenzene, C6H4Cl2
B) naphthalene, C10H8
C) methanol, C10H20O
D) some other compound
2. Compared to a 1.0 M aqueous solution of a nonelectrolyte, a 1.0 M solution of an electrolyte will have a
A) higher melting point and higher boiling point.
B) higher melting point and lower boiling point.
C) lower melting point and higher boiling point.
D) lower melting point and lower boiling point.
3. Which of the following pairs, when mixed together, do not form a solution?
A) C6H12(l) and CCl4(l)
B) NH3(g) and H2O(l)
C) NaCl(s) and H2O(l)
D) H2O(l) and C5H10(l)
4. An aqueous solution of ethylene glycol, C2H6O2, has a mol fraction of ethylene glycol of 0.162. The molality of the same solution is,
A) 6.77 m
B) 6.77 m
C) 10.8 m
D) 16.2 m
FINAL EXAM PART 2 2
5. What is the activation energy of a reaction if the rate constant increases by a factor of 10 when the temperature is raised from 303 K to 333 K.
A) 64 kJ
B) 46 kJ
C) 33 kJ
D) 30 kJ
6. The decomposition of NO
follows simple second order kinetics. In a particular experiment, it takes 2000 seconds for the concentration of NO to fall from 2.80 x 10-3 M to 2.00 x 10-3 M. If a second experiment is performed with the initial concentration of NO at 0.0820 M, calculate how long it will take for the concentration to fall to 4.10 x 10-2 M.
A) 1.71 x 102 s
B) 1.00 x 103 s
C) 2.86 x 103 s
D) 4.12 x 103 s
7. A proposed mechanism for the reaction
is as follows;
The rate law is;
A) rate = k[NO][Br2]
B) rate = k[NO]2[Br2]
C) rate = k[NO][NOBr2]
D) rate = k[NO]2
FINAL EXAM PART 2 3
8. A mixture of hydrogen and nitrogen are allowed to come to equilibrium at a specified temperature according to the reaction,
Analysis of the equilibrium mixture shows that it contains 1.5 mol NH3, 2.0 mol
N2, 3.0 mol H2. How many moles of H2 were present at the beginning of the
9. If the temperature is raised in an equilibrium system containing H2, N2, and NH3, it is found that the equilibrium constant for the formation of NH3 decreases. This indicates that the synthesis of ammonia from its elements
A) is exothermic.
B) is endothermic.
C) is impractical.
D) occurs without any change in energy.
10. The partial pressure of N2O is increased by
A) an increase in the volume of the container.
B) decreasing the temperature.
C) removing NO(g).
D) adding NO2(g).
11. Which value for an equilibrium constant, K, would indicate that the reaction
goes nearly to completion?
FINAL EXAM PART 2 4
12. A white solid is known to be one of the following: K2C2O4, CaCO3, NH4NO3, Ca(NO3)2. The substance is only slightly soluble in water. It dissolves readily in HCl, releasing a gaseous product. What is the compound?
13. Which substance, when added to water, will not change the pH?
14. When 40.00 mL of 0.0900 M NaOH is diluted to 100 mL and 30.00 mL of 0.100 M HCl are added. The pH of the resulting solution is
15. At body temperature (98.6 ºF = 37 ºC), Kw has a value of 2.4 x 10-14. If the pH of blood is 7.4 under these conditions, what is the concentration of OH-?
A) 1.0 x 10-7 M
B) 3.98 x 10-8 M
C) 2.51 x 10-7 M
D) 6.03 x 10-7 M
16. To prepare a buffer of pH = 3.2 equal concentration of a weak acid and its conjugate base should be mixed together. The best acid for preparing such a buffer would have a Ka of
A) 2.0 x 10-5
B) 6.0 x 10-4
C) 3.2 x 10-2
D) 4.0 x 10-6
FINAL EXAM PART 2 5
17. The pH of a 0.150 M Ca(OH)2 solution is
18. Propionic acid (Ka = 1.0 x 10-5) is titrated with a sodium hydroxide solution. In order to most accurately determine the endpoint of the titration, which indicator would be the best choice?
A) methyl violet, pH range where a color change occurs (0 - 2) B) bromcresol green, pH range where a color change occurs (4.0 - 5.6) C) phenolphthalein, pH range where a color change occurs (8.3 - 10.0) D) trinitrobenzene, pH range where a color change occurs (12.0 - 14.3)
19. Which substance would be about equally soluble in water and in 0.1 M HCl?
20. At 25 ºC, 400 mL of water can dissolve 0.00896 g of lead iodate, Pb(IO3)2. Calculate Ksp for lead iodate.
A) 2.88 x 10-6
B) 2.59 x 10-10
C) 2.60 x 10-13
D) 1.66 x 10-14
21. Which of the following chemical changes describes an endothermic process?
FINAL EXAM PART 2 6
22. Which of the following chemical changes is accompanied by a decrease in entropy?
23. If DHº is positive and DSº is positive for a chemical reaction then, the reaction is
A) spontaneous at all temperatures
B) spontaneous at high temperatures
C) spontaneous at low temperatures
D) nonspontaneous at all temperatures
24. Mercury batteries, like those used in electric watches, furnish a voltage of 1.35 v. If the overall oxidation-reduction reaction taking place in basic solution is
the anode reaction must be
25. Aluminum oxide may be electrolyzed at 1000 ºC to furnish aluminum metal. The cathode reaction is
To prepare 5.12 kg of aluminum metal by this method would require
A) 5.49 x 107 C of electricity
B) 1.83 x 107 C of electricity
C) 5.49 x 104 C of electricity
D) 5.49 x 101 C of electricity
FINAL EXAM PART 2 7
26. Calculate the cell potential, Ecell, for the reaction
A) +0.050 v
B) 0.00 v
C) -0.050 v
D) can not be determine without additional information
27. Given the following half-reactions
The measured cell potential for the spontaneous reaction
under standard conditions is +2.363 v. The pH of the solution in the cathode compartment must be
28. Carbon monoxide is toxic to humans because
A) it reacts with water to form carbonic acid.
B) it is strongly basic.
C) it is a strong oxidizing agent.
D) it binds strongly to hemoglobin.
29. Which of the following statements about properties of oxygen, O2, is false?
A) Oxygen is a colorless, odorless, tasteless gas.
B) Oxygen is the only elemental form of oxygen.
C) Air is the primary industrial source for oxygen.
D) Oxygen is pale blue in both the liquid and solid phase.
FINAL EXAM PART 2 8
AP Chemistry by Satellite
Final Exam Part 2
Student Name ______________________________
Teaching Partner's Name ______________________________
High School ______________________________
Write the letter indicating the most correct answer to each of the 29 questions, clearly and carefully using capital letters. Each question has only one correct answer. Your score will be based on the number of correct answers, so it is to your benefit to guess even if you are unsure of the correct answer.
Multiple Choice Answers
|1. B||11. A||21. A|
|2. C||12. B||22. B|
|3. D||13. D||23. B|
|4. C||14. B||24. B|
|5. A||15. D||25. A|
|6. A||16. B||26. A|
|7. A||17. C||27. A|
|8. D||18. C||28. D|
|9. A||19. A||29. B|
|10. B||20. C|
Final Exam Part 2 SCORE
_______ · 3.45 = ________