Chemistry 1211 Practice Exam II Page 9

Chemistry 1211

Practice Exam II

Name______

This practice exam is designed to be similar to a second exam for the course. You should attempt this exam without the use of notes, books, or help and you should time yourself, although this practice test is probably longer than the real exam.

When finished, grade your exam using the exam answers, but do not look at the answers before you attempt the exam. You should then be able to tell how well prepared you are for the first exam of the course. Use this as an evaluation tool to help you decide on areas that may need more study time. Good luck, let me know if I can be of any assistance.

7 -1 -34 RH = 1.097 x 10 m h = 6.626 x 10 joules·sec

c = 3.0 x 108 m/sec 1 Hz = 1 cycle/sec = 1 sec-1

hc  1 1  E  h   - (2.18 x 10-18 J) -   2 2  λ  nf ni 

 1   1  E  (-hcR )  - (2.18 x 10-18 J)  H  2   2   n   n  h -9   1 nm = 10 meters c = υ mv Chemistry 1211 Practice Exam II Page 2

The first part of the exam consists of 50 multiple choice questions.

1. What is the molarity of a solution prepared by mixing 9.5 g C3H8O3 (MW = 92) with enough water to have a total volume of 31.5 ml?

a. 0.10 M b. 0.40 M c. 3.3 x 10-3 M d. 3.3 M e. 300 M

2. What is the result of mixing solutions of sodium sulfate with lead nitrate? Data: lead sulfate is a solid.

a. Na2SO4 (aq) + Pb(NO3)2 (s) b. NaNO3 (aq) + PbSO4 (g) c. NaNO3 (aq) + PbSO4 (s) d. NaNO3 (s) + PbSO4 (aq) e. It is not possible to tell from the information given.

3. In the following reaction, determine which substance is the reducing agent. + 3 H2S + 2 NO3¯ + 2 H  S + 2 NO + 4 H2O

+ a. H2S b. NO3¯ c. H d. S e. NO f. H2O g. None of these

4. Which of the following is a form of potential energy? a. heat b. light c. dynamite exploding d. compressed spring e. electricity

5. If two objects are in contact with each other and object 1 is at a higher temperature than object 2; which of the following statements is correct? a. heat cannot flow between the two objects b. heat flows from object 2 to object 1 c. heat flows from object 1 to object 2 d. the temperature of object 1 should increase e. the temperature of object 2 will remain the same

6. Many hand held laser pointers emit 650 nm light. What is the frequency of this light?

a. 2.2 x 10-15 Hz b. 5.1 x 10-3 Hz c. 2.0 x 102 Hz d. 1.5 x 106 Hz e. 4.6 x 1014 Hz

7. Which of the following sets of quantum numbers refers to a 4f orbital?

a. n = 4; l = 1; ml = 0; ms = +½ b. n = 4; l = 2; ml = -1; ms = -½

c. n = 4; l = 3; ml = -2; ms = -½ d. n = 4; l = 4; ml = 0; ms = +½

e. n = 4; l = 4; ml = -4; ms = +½

8. How many orbitals have the following quantum numbers: n = 6; l = 2; ml = -2?

a. 0 b. 1 c. 2 d. 3 e. 5 f. 6 Chemistry 1211 Practice Exam II Page 3

9. What is the ground state electron configuration of 25Mn?

a. 1s22s22p63s23p64s13d6 b. 1s22s22p63s23p64s23d5 c. 1s22s22p63s23p63d7 d. 1s22s22p63s23p63d5 e. 1s22s22p63s23p64s24p5

10. What is the symbol of the atom or ion with the following orbital diagram? 1s 2s 2p 3s 3p 3d 4s (↑↓) (↑↓) (↑↓)(↑↓)(↑↓) (↑↓) (↑↓)(↑↓)(↑↓) (↑↓)(↑↓)(↑↓)(↑ )(↑ ) (↑↓)

-2 +2 -2 a. 26Fe b. 26Fe c. 27Co d. 28Ni e. 28Ni

11. All of the following statements are false EXCEPT…

a. the wavelength of light is directly proportional to its frequency. b. the frequency of light is inversely proportional to its energy. c. the energy of a photon of light is inversely proportional to its wavelength. d. the frequency of light is directly proportional to the speed of light (in a vacuum). e. the wavelength of light is directly proportional to the speed of light (in a vacuum).

12. The energy required to break one mole of hydrogen bonds in H2 (g) is 436 kJ. What is the longest wavelength of light that is capable of breaking this bond?

a. 91.7 nm b. 103 nm c. 192 nm d. 208 nm e. 274 nm

13. The Schrodinger wave equation…

a. proves electrons have positive and negative spins. b. calculates the precise position and momentum of an electron at any given time. c. is used to compute the wavelength of small particles. d. can be solved to find the probability of finding an electron in a region of space. e. proves that photons are particles.

14. Which of the following sets of quantum numbers refers to a 3p orbital?

a. n = 3; l = 0; ml = 0; ms = +½ b. n = 3; l = 1; ml = -1; ms = +½

c. n = 3; l = 2; ml = 1; ms = +½ d. n = 3; l = 3; ml = -2; ms = +½

e. n = 3; l = 3; ml = 3; ms = +½

15. What type of orbital is designated by: n = 5; l = 2; ml = 1

a. 5d b. 2f c. 5p d. 2s e. 5s Chemistry 1211 Practice Exam II Page 4

16. The Pauli exclusion principle state that…

a. no two electrons from a given atom can have the same spin. b. no two electrons from an given atom can have the same four quantum numbers. c. two electrons can occupy an orbital if they have opposite spins. d. two electrons can occupy an orbital if they have the same spin. e. two electrons can occupy an orbital if they have opposite charges.

17. According to the Bohr model for the hydrogen atom, the energy necessary to excite an electron from n = 5 to n = 6 is ______the energy necessary to excite an electron from n = 3 to n= 4. a. greater than b. equal to c. less than d. either equal to or greater than e. either less than or equal to

18. All of the following sets of quantum numbers are allowed EXCEPT…

a. n = 1; l = 0; ml = 1; ms = -½ b. n = 2; l = 1; ml = 0; ms = +½

c. n = 3; l = 1; ml = -1; ms = -½ d. n = 4; l = 3; ml = -1; ms = -½

e. n = 6; l = 3; ml = -3; ms = +½

19. Hund’s rule predicts that…

a. the most stable electronic structure of an atom has electron spins paired. b. no two electrons will share the same orbital. c. electrons in an orbital have equal but opposite charges. d. electrons must have opposite spins to share an orbital. e. when several orbitals of equal energy are available, as in a given subshell, electrons enter singly with parallel spins.

20. Elements and compounds with unpaired electrons are attracted to a magnetic field. These materials are called paramagnetic. Which of the following elements or ions are paramagnetic in the ground state?

a. 12Mg b. 26Fe c. 10Ne d. 20Ca e. 30Zn

21. Which of the following solutions contains the largest number of moles of chloride ions?

a. 10.0 mL of 0.500 M BaCl2 b. 4.00 mL of 1.000 M NaCl c. 7.50 mL of 0.500 M FeCl3 d. 25.00 mL of 0.400 M KCl e. 30.00 mL of 0.100 M CaCl2 Chemistry 1211 Practice Exam II Page 5

22. Consider the following reactions:

AgNO3 (aq) + Zn (s)  Ag (s) + Zn(NO3)2 (aq)

Zn(NO3)2 (aq) + Co (s)  No Reaction

AgNO3 (aq) + Co (s)  Ag (s) + Co(NO3)2 (aq)

Which is the correct order of increasing activity for these metals?

a. Ag < Zn < Co b. Co < Ag < Zn c. Co < Zn < Ag d. Ag < Co < Zn e. Zn < Co < Ag

+ 23. How many moles of K are present in 343 mL of a 1.27 M solution of K3PO4?

a. 0.436 b. 1.31 c. 0.145 d. 3.70 e. 11.1

24. Calculate the concentration (M) of sodium ions in a solution made by diluting 50.0 mL of a 0.874 M solution of sodium sulfide to a total volume of 250.0 mL.

a. 0.175 M b. 4.37 M c. 0.525 M d. 0.350 M e. 0.874 M

25. The molarity of an aqueous solution containing 52.5 g of sucrose, C12H22O11, in 35.5 mL of solution is…

a. 5.46 b. 1.48 c. 0.104 d. 4.32 e. 1.85

26. How much 0.827 M KOH is required for neutralization in a titration of 35.00 mL of 0.737 M H2SO4?

a. 35.0 mL b. 1.12 mL c. 25.8 mL d. 62.4 mL e. 39.3 mL

27. The value of ∆H for the reaction below is -790 kJ. The enthalpy change for the reaction of 0.95 grams of S would be…

2 S (s) + 3 O2 (g)  2 SO3 (g)

a. 23 kJ b. -23 kJ c. -12 kJ d. 12 kJ e. -790 kJ

28. The value of ∆H for the reaction below is -1107 kJ. The ∆H for the reaction of 15.75 g of Ba (s) completely reacting with oxygen is…

2 Ba (s) + O2 (g)  2 BaO (s)

a. 20.8 kJ b. 63.5 kJ c. 114 kJ d. 70.3 kJ e. 35.1 kJ

29. The specific heat capacity of lead is 0.13 J/g·K. How much heat (in J) is required to raise the temperature of 15 g of lead from 22 °C to 37 °C? Chemistry 1211 Practice Exam II Page 6

a. 2.0 b. -0.13 c. 5.8 x 10-4 d. 29 e. 0.13

30. Given the following reactions: (1) 2 NO  N2 + O2 ∆H = -180 kJ

(2) 2 NO + O2  2 NO2 ∆H = -112 kJ

What is the ∆H for: N2 + 2 O2  2 NO2

a. 68 kJ b. -68 kJ c. -292 kJ d. 292 kJ e. -146 kJ

31. Given the data in the table here, calculate the ∆H for the reaction: Substance ∆Hf kJ/mole 4 NH3 (g) + 5 O2 (g)  4 NO (g) + 6 H2O(l) H2O(l) -286

H2O(g) -242

a. -1172 kJ b. -150 kJ c. -1540 kJ d. -1892 kJ e. other NO (g) 90 NO2 (g) 34 32. The internal energy of a system can be increased by… HNO3 (aq) -207 NH3 (g) -46 (1) transferring heat from the surroundings to the system (2) transferring heat from the system to the surroundings (3) doing work on the system

a. (1) only b. (2) only c. (3) only d. (1) and (3) e. (2) and (3)

33. Which of the following is a statement of Hess’s law?

a. If a reaction is carried out in a series of steps, the ∆H for the reaction will equal the sum of the enthalpy changes for the individual steps. b. If a reaction is carried out in a series of steps, the ∆H for the reaction will equal the product of the enthalpy changes for the individual steps. c. The ∆H for a process in the forward direction is equal in magnitude and opposite in sign to the ∆H for the process in the reverse direction. d. the ∆H for a process in the forward direction is equal to the ∆H for the process in the reverse direction. e. The ∆H of a reaction depends on the physical states of the reactants and products.

34. The specific heat capacity of liquid mercury is 0.14 j/g·K. How many joules of heat are needed to raise the temperature of 5.00 g of mercury from 15.0 °C to 36.5 °C?

a. 7.7 x 102 b. 15 c. 36 d. 0.0013 e. 1.7 Chemistry 1211 Practice Exam II Page 7

35. What is the frequency of electromagnetic radiation that has a wavelength of 0.53 m?

a. 5.7 x 108 b. 1.8 x 10-9 c. 1.6 x 108 d. 1.3 x 10-33 e. 1.3 x 1033

36. The wavelength of a photon that has an energy of 5.25 x 10-19 joules is…

a. 3.79 x 10-7 m b. 2.64 x 106 m c. 2.38 x 1023 m d. 4.21 x 10-24 m e. 3.79 x 107 m

37. The energy of a photon that has a frequency of 8.21 x 1015 sec-1 is… (in joules)

a. 8.08 x 10-50 b. 1.99 x 10-25 c. 5.44 x 10-18 d. 1.24 x 1049 e. 1.26 x 10-19

38. Using Bohr’s equation for the energy levels of the electron in the hydrogen atom, determine the energy (joules) of an electron on the n=4 level.

a. -1.36 x 10-19 b. -5.45 x 10-19 c. -7.34 x 1018 d. -1.84 x 10-29 e. +1.84 x 10-29 39. An electron in a Bohr hydrogen atom has an energy of -1.362 x 10-19 joules. The value for n for this electron is…

a. 1 b. 2 c. 3 d. 4 e. 5 f. other

40. A spectrum containing only specific wavelengths is call a…

a. line spectrum b. continuous spectrum c. visible spectrum d. Rydberg spectrum e. Bohr spectrum

41. When the electron in a hydrogen atom moves from n=6 to n=2, what would be the wavelength (nm) of the photon emitted?

a. 93.8 b. 434 c. 487 d. 657 e. 411

42. What is the de Broglie wavelength (m) of a 2.0 kg object moving at a speed of 50 m/sec?

a. 6.6 x 10-36 b. 1.5 x 1035 c. 5.3 x 10-33 d. 2.6 x 10-35 e. 3.8 x 1034

43. How many p-orbitals are occupied in a Ne atom?

a. 1 b. 2 c. 3 d. 5 e. 6 Chemistry 1211 Practice Exam II Page 8

44. How many electrons occupy p-orbitals in a Ne atom?

a. 1 b. 2 c. 3 d. 6 e. 12

45. [Ar]4s23d104p3 is the electron configuration for…

a. As b. V c. P d. Sb e. Sn

46. How many unpaired electrons in the ground state of a fluorine atom?

a. 0 b. 1 c. 2 d. 3 e. 4 f. 5 g. 6 h. more

47. All of the orbitals in a given subshell have the same value of which quantum number(s)?

a. principal b. azimuthal c. magnetic d. spin e. (a) & (b) f. (b) & (c)

48. If the quantum numbers listed below are in the order: n, l, ml, which set is not possible?

a. 2, 0, 0 b. 2, 1, -1 c. 3, 1, -1 d. 1, 1, 1 e. 3, 2, 1 f. all look good

49. Which orbital below is degenerate (same energy) with 5py?

2 a. 5s b. 5px c. 4py d. 5dxy e. 5d

50. How many different principal quantum numbers can be found in the ground state electron configuration of nickel?

a. 2 b. 3 c. 4 d. 5 e. 6

The remainder are “show your work” type of problems. Chemistry 1211 Practice Exam II Page 9

51. What mass of iron (AW = 55.85) results when 8.55 g of CO (MW = 28.0) is mixed with 14.3 g of Fe2O3 (MW = 159.7)? Show all of your work clearly for full credit.

Fe2O3 + 3 CO  2 Fe + 3 CO2

52. Calculate the wavelength of the line in the Lyman series that results from the transition n = 3 to n = 1. Show all of your work for full credit.

53. Balance each of the following REDOX reactions using the half-reaction method. Show your work clearly.

+ A. Ag + AsH3  As4O2 + Ag (Acidic Solution)

B. Al + H2O  Al(OH)4¯ + H2 (Basic Solution)

C. Na2Cr2O7 + HCl  NaCl + CrCl3 + Cl2 (Acidic Solution)

54. Consider the reaction shown below. Phosphorus is produced by this reaction in 75% yield. Calculate the mass of phosphorus (AW = 31.0) produced by mixing 875 g of Ca3(PO4)2 (MW = 310.3) and an excess of carbon (AW = 12) and silicon dioxide (AW = 60.1). Show all of your work clearly for full credit.

2 Ca3(PO4)2 + 10 C + 6 SiO2  P4 + 6 CaSiO3 + 10 CO Chemistry 1211 Practice Exam II Page 10

Answers: Don’t look until you have attempted the problems. (If you find errors, let me know)

Multiple Choice

1. d 2. c 3. a 4. d 5. c 6. e 7. c 8. b 9. b 10. d 11. c 12. e 13. d 14. b 15. a 16. b 17. c 18. a 19. e 20. b 21. c 22. d 23. b 24. d 25. d 26. d 27. c 28. b 29. d 30. a 31. a 32. d 33. a 34. b 35. a 36. a 37. c 38. a 39. d 40. a 41. e 42. a 43. c 44. d 45. a 46. b 47. e 48. d 49. b 50. c

51. 10.00 grams

52. 1.02 x 10-7 m or 102 nm

53. + + A. 16 Ag + 4 AsH3 + 2 H2O  As4O2 + 16 Ag + 16 H

- B. 2 Al + 6 H2O + 2 OH  2 Al(OH)4¯ + 3 H2

C. Na2Cr2O7 + 14 HCl  2 NaCl + 2 CrCl3 + 3Cl2 + 7 H2O

54. 131.13 grams