CHEM 1031 - Practice Test Final Exam PDF

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Document contains unique questions for Final test preparation and it's helpful .!! Also answer key is on the last page..(Not solved only right answers)...

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CHEM 1031 – PRACTICE FINAL EXAM (Constants and the Periodic Table are on page 10. The answer key is on page 11.)

1. What is the chemical symbol for potassium? A. Po

B. K

C. Pm

D. P 3.9  7.2 ? 0.3128 D. 2

2. How many significant figures should be recorded for the result of the calculation: A. 5

B. 4

C. 3

3. What volume of alcohol will have the same mass as 49.3 cm3 of aluminum. (Density of alcohol = 0.860 g/cm3; density of aluminum = 2.70 g/cm3). A. 15.7 cm3

B. 18.3 cm3

C. 21.3 cm3

D. 155. cm3

4. A burner delivers 80.0 kcal of energy per minute. How many kilojoules of energy will be delivered in 2.0 hours? (1 calorie = 4.184 J). A. 40. kJ

B. 11. kJ

C. 2.3 x 103 kJ

D. 4.0 x 104 kJ

C. H2O(g)

D. O2(g)

C. silver tarnishing

D. grass dying

5. Which represents a mixture of two elements?

6. What is inside the bubbles when liquid water boils? A. air

B. H2(g) and O2(g)

7. Which is a physical change? A. wood burning 8. The symbol

B. gold melting

42 20 X represents

an element with how many neutrons?

A. Ca with 22 neutrons B. Ca with 42 neutrons

C. Mo with 22 neutrons D. Mo with 42 neutrons

2 9. Rutherford directed alpha particles at a thin piece of gold foil. He observed that only a few particles were sharply deflected. How did he interpret this observation? A. B. C. D.

Electrons can only have specific quantized energies. Atoms have isotopes with different masses and numbers of neutrons. Electrons move in circular orbits within the atom. All protons in an atom are concentrated in a relatively small volume.

10. What is the correct symbol for an ion of bismuth with 80 electrons and 124 neutrons? A.

124 3  83 Bi

B.

207 3  83 Bi

C.

207 3  83 Bi

D.

124 3  83 Bi

11. Vanadium (V) has only two naturally occurring isotopes, vanadium-50 and vanadium-51. Which is a valid conclusion that can be drawn about vanadium? A. B. C. D.

The abundance of each isotope is 50%. Vanadium-51 is more abundant than vanadium-50. All vanadium atoms have a mass of 50.94 amu. Vanadium-50 is more abundant that vanadium-51.

12. How many moles of iron are in 35.6 g of Fe2O3? A. 0.446 mol

B. 4.49 mol

C. 0.223 mol

D. 8.97 mol

13. How many oxygen atoms are in a 5.24 g sample of (NH4)2Fe(SO4)2∙6H2O (molar mass = 392. g/mol). A. 8.05 x 1021

B. 1.13 x 1023

C. 6.44 x 1022

D. 4.42 x 1025

14. What is the charge on the iron ions in (NH4)2Fe(SO4)2∙6H2O? A. 4+

B. 3+

C. 2+

D. 1+

15. What is the mass percent of hydrogen in (NH4)2Fe(SO4)2∙6H2O? A. 5.14%

B. 4.11%

C. 3.09%

D. 2.06%

16. The mass of the average grape is 0.25 g and the mass of a bottle of wine is 1.3 kg. What is the number of bottles of wine whose total mass is the same as 1.0 mol of grapes? A. 1.2 x 1020

B. 3.1 x 1021

C. 1.2 x 1023

D. 2.0 x 1020

17. What is the formula of the compound formed between chromium(III) ions and carbonate ions? A. CrCO3

B. Cr3(CO3)2

C. Cr2(CO3)3

18. What is the name of S2F4? A. sulfur(IV) fluoride C. disulfur tetraflouride

B. disulfur tetrafluoride D. disulfur tetrafluorine

D. Cr(CO3)3

3 19. Which acid is paired with its correct name? A. HClO4 – hypochlorous acid C. HNO2 – nitrous acid

B. H2SO4 – sulfurous acid D. H3PO4 – phosphorous acid

20. The name of MgSO4∙7H2O is? A. magnesium(II) sulfate heptahydride C. magnesium sulfate heptahydrate

B. magnesium(II) sulfate heptahydrate D. magnesium sulfate heptahydride

21. What is the coefficient for NH3 when the equation is balanced using the smallest, whole number coefficients? ___ NH3(g) + ___ O2(g) Æ ___ NO(g) + ___ H2O(g) A. 4

B. 3

C. 2

D. 1

22. Which could be both an empirical formula and a molecular formula? A. CH3COOH

B. Ca2O2

C. C12H22O11

D. S8

23. Which could be the molecular formula of a compound that contains 54.5% C, 9.20% H, and 36.3% O? A. C6HO4

B. C5H9O2

C. CHO

D. C4H8O2

24. How many moles of N2 are produced by the decomposition of 0.250 mol of LiN3 in the reaction: 2 LiN3(s) Æ 2 Li(s) + 3 N2(g) ? A. 1.250 mol

B. 0.750 mol

C. 0.375 mol

D. 0.167 mol

25. What mass of NH4ClO4 (molar mass = 117.49 g/mol) is needed to completely react with 20.0 g of aluminum in the reaction: 6 NH4ClO4(s) + 10 Al(s) Æ 3 N2(g) + 9 H2O(g) + 5 Al2O3(s) + 6 HCl(g) ? A. 145. g

B. 12.0 g

C. 52.3 g

D. 95.1 g

26. When 3.00 g of Ag react with excess O2, 2.50 g of Ag2O is produced in the reaction: 4 Ag(s) + O2(g) Æ 2 Ag2O(s). What is the percent yield? A. 93.1%

B. 77.6%

C. 38.8%

D. 60.0%

27. In the reaction: 4 B(g) + 3 O2(g) Æ 2 B2O3(g), 0.60 mol of B and 0.30 mol of O2 react. When the reaction is complete, which of the following is true? A. B. C. D.

0.30 mol of B2O3 is produced, all the B is used up, and 0.10 mol of O2 remains unreacted. 0.20 mol of B2O3 is produced, all the O2 is used up, and 0.20 mol of B remains unreacted. 0.30 mol of B2O3 is produced, all the O2 is used up, and 0.10 mol of B remains unreacted. 0.20 mol of B2O3 is produced, all the B is used up, and 0.20 mol of O2 remains unreacted.

4 28. Which is the least soluble in water? A. NaCl

B. CaCl2

C. PbCl2

D. FeCl3

29. Which is the net ionic equation for the reaction between aqueous solutions of sodium carbonate and hydrochloric acid? A. B. C. D.

2 Na+(aq) + CO32–(aq) + 2 H+(aq) + 2 Cl–(aq) Æ H2CO3(aq) + 2 NaCl(aq) CO32–(aq) + 2 H+(aq) Æ H2(g) + CO2(g) + O2(g) Na+(aq) + CO3–(aq) + H+(aq) + Cl–(aq) Æ CO2(g) + NaCl(s) + H2O(l) CO32–(aq) + 2 H+(aq) Æ CO2(g) + H2O(l)

30. Which equation describes a process in which no evidence of a reaction occurred? A. B. C. D.

Ca(NO3)2(aq) + 2 LiBr(aq) Æ CaBr2(aq) + 2 LiNO3(aq) Na2S(aq) + 2 HCl(aq) Æ 2 NaCl(aq) + H2S(g) Zn(s) + CuCl2(aq) Æ ZnCl2(aq) + Cu(s) Ni(NO3)2(aq) + Na2S(aq) Æ NiS(s) + 2 NaNO3(aq)

31. When aqueous solutions of copper(II) nitrate and ammonium sulfide react, the formula of the precipitate that forms is: A. CuS

B. NH4NO3

C. CuSO4

D. Cu(NH3)2

32. What is the concentration of the chloride ion in a solution that is 0.300 M NaCl and 0.300 M AlCl3? A. 1.200 M

B. 0.900 M

C. 0.600 M

D. 0.300 M

33. How many milliliters of 3.5 M NaCl must be diluted down to prepare 0.25 L of 0.45 M NaCl? A. 0.032 mL

B. 32. mL

C. 1.6 x 102 mL

D. 1.9 x 103 mL

34. How many grams of Na2C2O4 is in 175 mL of a 3.50 M Na2C2O4(aq) solution? A. 82.1 g

B. 6.70 g

C. 8.21 x 103 g

D. 2.86 x 10–3g

35. What volume of 0.0650 M HCl is required to react with excess Pb(NO3)2 to produce 2.78 g of PbCl2? Pb(NO3)2(aq) + 2 HCl(aq) Æ PbCl2(s) + 2 HNO3(aq). (Molar mass of PbCl2 = 278.11 g/mol) A. 85.5 mL

B. 308. mL

C. 154. mL

D. 1.30 mL

36. A moveable piston is filled with 35.0 L of an ideal gas at a pressure of 1.10 atm and at a temperature of 25 oC. What temperature is required that will cause the volume and the pressure to double? A. 919 oC

B. 596 oC

C. 323 oC

D. 100 oC

5 37. A sample of CO2 occupies 6.00 L at 25 oC and 700 mmHg. What is the volume of CO2 at STP? A. 4.17 L

B. 5.06 L

C. 6.03 L

D. 22.4 L

38. At 1.00 atm pressure and 0 oC, 1.783 g of which gas would occupy 1.00 L? A. Ne

B. Ar

C. Kr

D. Xe

39. A mixture of 2 gases, one of which is oxygen, is released together from one end of a tube that is 2.5 m long. If it takes 6.3 s for the oxygen to effuse to the other end of the tube and 9.4 s for the other gas to effuse the same distance, what is the identity other gas? A. Cl2

B. N2

C. Ar

D. C2H2

40. What volume of hydrogen can be produced at 20.0 oC and 1.00 atm from 2.70 g of aluminum when it reacts with excess HCl in the reaction: 2 Al(s) + 6 HCl(aq) Æ 2 AlCl3(aq) + 3 H2(g) ? A. 365 L

B. 3.61 L

C. 2.41 L

D. 0.246 L

B. N2(l)

C. H(g)

D. Zn(s)

41. Which has ' H of = 0? A. NaCl(aq)

42. Which of the following physical changes is endothermic? A. I2(s) Æ I2(l)

B. I2(l) Æ I2(s)

C. I2(g) Æ I2(l)

D. I2(g) Æ I2(s)

43. A 0.825 g sample of copper at 176.00 oC is placed in an insulated cup containing 10.0 g of water at 20.00 oC. The final temperature of the mixture is 21.18 oC. What is the specific heat capacity of copper? Specific heat capacity of water = 4.184 J/g∙oC. A. 59.8 J/g∙oC

B. 0.387 J/g∙oC

C. 24.6 J/g∙oC

44. What does the potential energy diagram depict?

A. B. C. D.

An endothermic reaction in which heat is absorbed from the surroundings. An endothermic reaction in which heat is lost to the surroundings. An exothermic reaction in which heat is absorbed from the surroundings. An exothermic reaction in which heat is lost to the surroundings.

D. 0.340 J/g∙oC

6 45. Calculate 'H for the reaction: given: and: A. –494 kJ

PCl5 Æ PCl3 + Cl2 P4 + 6 Cl2 Æ 4 PCl3 P4 + 10 Cl2 Æ 4 PCl5

B. –124 kJ

'H = –1280 kJ 'H = –1774 kJ

C. +494 kJ

D. + 124 kJ

46. Calculate ' Ho for the reaction: CaC2(s) + 2 H2O(l) Æ Ca(OH)2(aq) + C2H2(g), given the ' H of values (all in kJ/mol): CaC2(s) = –59.8; H2O(l) = –285.8; Ca(OH)2(aq) = –1002.8; C2H2(g) = +225.7. A. –431.5 kJ

B. +145.7 kJ

C. –1,288.9 kJ

D. –145.7 kJ

47. Estimate the N–H bond energy given: N2(g) + 3 H2(g) Æ 2 NH3(g) 'H = –97 kJ and the bond energies: N≡N = 941 kJ/mol; H–H = 436 kJ/mol. A. 213 kJ/mol

B. 246 kJ/mol

C. 359 kJ/mol

D. 391 kJ/mol

48. Which of these types of electromagnetic radiation has the shortest wavelength? A. Infrared

B. Visible light

C. Radio waves

D. Ultraviolet

49. What is the energy of a photon with a wavelength of 93.8 nm? A. 2.12 x 1015 J

B. 1.07 x 107 J

C. 3.13 x 10–16 J

D. 2.12 x 10–18 J

50. Which transition for an electron in a hydrogen atom results in the lowest energy emission? A. n = 3 Æ n = 1

B. n = 3 Æ n = 2

C. n = 4 Æ n = 3

D. n = 2 Æ n = 1

51. Which set of quantum numbers is allowed? A. n = 1, l = 0, ml = –1, ms = –½ C. n = 1, l = 0, ml = 0, ms = +½

B. n = 1, l = 0, ml = 1, ms = –½ D. n = 1, l = 1, ml = 0, ms = +½

52. How many electrons in an atom can have the quantum numbers n = 2 and l = 1? A. 8

B. 6

53. Which of the following is a 2pz orbital?

C. 4

D. 2

7

54. What is the ground state electron configuration of phosphorus? A. [Ne]3s23p3

B. [Ar]3s23p3

C. 1s22s23s23p3

D. [Ar]2s22p3

55. What is the ground state electron configuration of the iron(III) cation? A. [Ar]3d5

B. [Ar]4s13d4

C. [Ar]4s23d3

D. [Ar]4s23d6

56. How many unpaired electrons does a cobalt (Co) atom have in the ground state? A. 7

B. 5

C. 3

D. 1

57. Which of the following is paramagnetic in the ground state? A. Br–

B. K–

C. Zn

D. N2–

58. Tellurium (Te) has an atomic radius of 143 pm and a first ionization energy of 869 kJ/mol. Predict the properties of an atom with a greater atomic number than Te and in the same period.

A. B. C. D.

Atomic Radius (pm) 167 141 133 156

First Ionization Energy (kJ/mol) 813 834 1009 1105

59. Which comparisons of radii are correct? (i) S2– > S

(ii) K+ > K

(iii) F > F–

(iv) Sr > Sr2+

A. (iii) and (iv)

B. (ii) and (iii)

C. (i) and (iv)

D. (i) and (iii)

60. Which third period element has the following set of ionization energies (all in kJ/mol)? IE1 = 787, IE2 = 1577, IE3 = 3232, IE4 = 4356, IE5 = 16091, IE6 = 19805, IE7 = 23780, IE8 = 29287 A. Ar

B. P

C. Si

D. Ge

61. Which of the following structures represents another reasonable resonance structure for:

8

62. Which characteristic of benzene requires the use of both resonance structures to describe a consistent structure for benzene?

A. molecular shape C. hybridization of carbon

B. empirical formula D. carbon-carbon bond lengths

63. Which of the following has a molecular shape that is trigonal planar? A. BF3

B. ClF3

C. NF3

64. What is the electron geometry of BrF5? A. trigonal bipyramidal C. square pyramidal

B. octahedral D. trigonal pyramidal

65. What is the electron geometry of XeF4 according to VSEPR theory?

66. What is the geometry of the nitrite (NO2–) anion?

D. PF3

9 A. linear

B. bent

C. trigonal planar

D. trigonal pyramidal

C. CS2

D. F2

67. Which of the following is polar? A. BeCl2

B. SO2

68. What is the hybridization of the carbon atom in carbon monoxide? A. sp

B. sp2

C. sp3

D. sp3d

69. What is the hybridization of carbon before and after this reaction?

A. B. C. D.

Before reaction sp2 sp2 sp3 sp3

After reaction sp2 sp3 sp2 sp4

70. How many sigma (V) and pi (S) bonds are in this molecule?

A. 8V, 2S

B. 7V, 1S

C. 7V, 2S

D. 8V, 1S

10

11

ANSWER KEY B 1 2 C 3 D 4 D 5 D 6 C 7 B 8 A D 9 10 B 11 B 12 A 13 B 14 C 15 A 16 A 17 C 18 B 19 C 20 C 21 A 22 C 23 D 24 C 25 C 26 B 27 B 28 C 29 D 30 A 31 A 32 A 33 B 34 A 35 B

36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70

A B B A B D A B A D D D D D C C B C A A C D C C C D D A B D B B A B D...