Chem 1100 Pre-Test 3. Multiple Choice Identify the choice that best completes the statement or answers the question.

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1 Chem 1100 Pre-Test 3 Multiple Choice Identify the choice that best completes the statement or answers the question. 1. An open-tube manometer is used to measure the pressure in a flask. The atmospheric pressure is 756 torr and the Hg column is 8.5 cm higher on the open end. What is the pressure in the flask? a mmhg b. 841 cm Hg c. 841 torr d. 671 torr e mm Hg 2. A sample of gas occupies a volume of 1.60 L at a pressure of 720. torr. What would be the pressure of this gas if it were compressed to 1.20 L at the same temperature? a torr b torr c torr d torr e torr 3. A gas sample occupies 1.00 L at 120. C and 1.00 atm. What volume will it occupy at STP? a L b L c L d L e L 4. A sample of neon occupies 4.50 liters at 30.0 C and 2.50 atmospheres. What volume will it occupy at torr and 300. C? a L b L c L d L e L 5. What is the volume occupied by 10.0 grams of NH 3 at STP, if it behaves ideally? a L b L c L d L e L 6. What is the molecular weight of a gas if gram of the gas occupies 48.7 ml at STP? a g/mol b g/mol c g/mol d g/mol e g/mol 7. How many moles of Argon would occupy 75 ml at 33 C and 1.07 atm?

2 a b c d e Calculate the density of O 2 gas (in g/l) at 1.22 atm and 25 C. a g/l b g/l c g/l d g/l e g/l 9. A mixture of gases containing 21.0 g of N 2, g of Cl 2 and 12.0 g of He at 14 C is in a 50.0-L container. What is the total pressure in the vessel? a. 1.8 atm b. 2.2 atm c. 2.5 atm d. 2.7 atm e. 3.2 atm 10. A mixture of gas contains g Ar and 1.95 g Xe and has a total pressure of 2.33 atm. What are the partial pressures of each gas? P Ar (atm) P Xe (atm) a b c d e What is the mole fraction of O 2 in a mixture of 2.00 g He, 12.0 g O 2, and 17.0 g N 2? a b c d e A 300.-mL sample of hydrogen, H 2, was collected over water at 21 C on a day when the barometric pressure was 748 torr. What mass of hydrogen is present? The vapor pressure of water is 19 torr at 21 C. a g b g c g d g e g 13. What total volume of gas (at STP) is produced by the electrolysis of 4 moles of H 2O? 2H 2O(g) 2H 2(g) + O 2(g) a L b L c. 3.0 L

3 d. 112 L e. 5.0 L 14. Calculate the weight of KClO 3 that would be required to produce liters of oxygen measured at 127 C and 760. torr. a g b g c g d g e g 2KClO 3(s) 2KCl(s) + 3O 2(g) 15. What is the order of increasing rate of effusion for the following gases? Ar, CO 2, He, N 2 a. N 2 < Ar < CO 2 < He b. Ar < CO 2 < He < N 2 c. Ar < He < CO 2 < N 2 d. CO 2 < N 2 < Ar < He e. CO 2 < Ar < N 2 < He 16. The van der Waals constant, b, in the relationship is a factor that corrects for a. deviations in the gas constant, R. b. the attractive forces between gas molecules. c. the tendency of the gas molecules to ionize. d. the average velocities of the gas molecules. e. the volume occupied by the gas molecules. 17. Which of the following statements is false? An increase in temperature will a. increase the molecular weight of the gas. b. increase the velocity of the gas molecules. c. increase the number of collisions per second. d. increase the average kinetic energy of the molecules. e. increase the root-mean-square velocity of the molecules. 18. Which of the following gases is expected to have the largest value for its van der Waals constant "b"? a. Ne b. O 2 c. H 2 d. CO e. CO Calculate the pressure of grams of ethylene gas (C 2H 4) in a 10.0 L container at 30.0 C. Do not assume ideal gas behavior. a = L 2 -atm/mol 2, b = L/mol. a atm b. 168 atm c atm d atm e atm

4 20. Which of the following interactions are the strongest? a. hydrogen bonding force b. ion-ion interactions c. permanent dipole force d. dispersion force e. London force 21. The boiling points of the halogens increase in the order F 2 < Cl 2 < Br 2 < I 2 due to the resulting increasing interactions. a. ion-dipole b. hydrogen-bonding c. ion-ion d. dispersion forces e. permanent dipole-dipole 22. The term used to describe resistance to flow of a liquid is. a. surface tension b. capillary action c. viscosity d. vapor pressure e. vaporization 23. Which of these liquids would have the highest surface tension at 25 C? a. Br 2 b. H 2O c. CCl 4 d. C 5H 12 e. CH 3OCH Which of the following boils at the highest temperature? a. C 2H 6 b. C 3H 8 c. C 4H 10 d. C 5H 12 e. C 6H Calculate the amount of heat required to raise the temperature of 165 g of water from 12.0 C to 88.0 C. (Sp. heat of H 2O = 4.18 J/g C) a kj b J c kj d kj e J 26. Calculate the amount of heat (in joules) required to convert 92.5 g of water at 25.0 C to steam at C. (Sp. heat of H 2O = 4.18 J/g C, Sp. heat of H 2O(g) = 2.03 J/g C, heat of vap. of H 2O = kj/g) a J b J c J d J e J

5 27. Which response has the following substances arranged in order of increasing boiling point? Ar, NaClO 3, H 2O, H 2Se a. NaClO 3 < H 2O < H 2Se < Ar b. NaClO 3 < H 2Se < H 2O < Ar c. Ar < NaClO 3 < H 2Se < H 2O d. Ar < H 2O < H 2Se < NaClO 3 e. Ar < H 2Se < H 2O < NaClO In a body-centered cubic lattice, how many atoms are contained in a unit cell? a. one b. two c. three d. four e. five 29. Which one of the following is an ionic solid? a. graphite b. nickel c. ammonium chloride d. silicon carbide, SiC e. sucrose, C 12H 22O Which one of the following is a molecular solid? a. NH 4Cl b. K c. SiC d. C 6H 6 e. KC 2H 3O Which one of the following substances is incorrectly matched with the kind of solid it forms? Substance / Kind of Solid a. sulfur dioxide / molecular b. graphite / covalent c. calcium bromide / ionic d. potassium / ionic e. methane / molecular 32. Metallic calcium crystallized in a face-centered cubic lattice, and the edge of the cube is 15.57Å. Calculate the density of calcium. a g/cm 3 b g/cm 3 c g/cm 3 d g/cm 3 e g/cm Which one of the following elements is considered a semiconductor? a. Li b. Fe c. Cl d. Ni

6 e. Si 34. Elements that have their highest energy electrons in a filled valence band that is separated from the conductance band by an energy difference much too large for electrons to jump between bands are called. a. semiconductors b. metals c. conductors d. insulators e. isomorphs 35. Which of the following solutions would not be expected to exist? a. MgCl 2 in CCl 4 b. NaCl in water c. Pentane, C 5H 12, in CCl 4 d. methanol, CH 3OH, in water e. Vegetable oil in mineral oil 36. At 25 C, 100 g of water will be saturated with 35.7 g of NaCl. Which word below describes the solution of 1.55 mol of NaCl dissolved in 250 ml of water? a. saturated b. unsaturated c. supersaturated d. metasaturated e. none of these apply 37. Calculate the molality of a solution that contains 25 g of H 2SO 4 dissolved in 40. g of H 2O. a. 3.2 m b. 4.4 m c. 6.4 m d. 13 m e. 14 m 38. What mass of water must be used to dissolve 20.0 grams of ethanol, C 2H 5OH, to prepare a molal solution of ethanol? a kg b kg c kg d kg e kg 39. What is the mole fraction of ethanol, CH 3CH 2OH, in an aqueous solution that is 20.0% ethanol by mass? a b c d e Which of the following is not a colligative property? a. osmotic pressure b. vapor pressure raising c. boiling point elevation d. freezing point depression

7 e. All of these are colligative properties 41. Which aqueous solution would have the lowest vapor pressure at 25 C? a. 1 M NaCl b. 1 M K 3PO 4 c. 1 M sucrose, C 12H 10O 11 d. 1 M MgCl 2 e. 1 M glucose, C 6H 12O At 40 C, the vapor pressure of heptane is 92 torr. If a solution is made of naphthalene in heptane and has a vapor pressure of 82 torr, what is the mole fraction of naphthalene? Assume ideal solution behavior. a b c d e Which of these aqueous solutions would be expected to have the highest boiling point? a m KCl b m NaOH c m K 2SO 4 d m Al 2(SO 4) 3 e m CH 3OH 44. The boiling point of pure water in Winter Park, CO ( elev ft), is 94 C. What is the boiling point of a solution containing 11.3 g of glucose (180 g/mol) in 55 ml of water in Winter Park? K b for water = C/m. a C b C c C d. 100 C e C 45. Calculate the freezing point of a solution that contains 68.4 g of sucrose (table sugar) in 300. g of water. One mole of sucrose is 342 g. K f for H 2O = 1.86 C/m. a C b C c C d C e C 46. Estimate the molecular weight of a biological macromolecule if a gram sample dissolved in 50.0 ml of benzene has an osmotic pressure of 9.76 torr at 25.0 C. a g/mol b g/mol c g/mol d g/mol e g/mol 47. What is the molality of a solution prepared by dissolving 10.0 grams of methylamine, CH 3NH 2, in 50.0 ml of ethanol, C 2H 5OH? The specific gravity of ethanol is

8 a m b m c m d m e m 48. A solution contains 10.0 g pentane, C 5H 12, 10.0 g hexane, C 6H 14 and 10.0 g benzene, C 6H 6. What is the mole fraction of hexane? a b c d e Calculate the mole fraction of ethanol, C 2H 5OH, in a solution that contains 230. grams of C 2H 5OH and 312 grams of benzene, C 6H 6. a b c d. 1.8 e Physical properties that depend on the but not the of solute particles in a given amount of solvent are called colligative properties. a. number; kind b. polarity; number c. number; polarity d. kind; number e. polarity; concentration 51. What is the vapor pressure of a aqueous solution containing 10 %(by weight) ethylene glycol (62 g/mol) at 25 C. P H2O = 24.3 torr at 25 C. a torr b torr c torr d torr e torr 52. Calculate the freezing point of a solution that contains 8.0 g of sucrose (C 12H 22O 11) in 100. g of H 2O. K f for H 2O = 1.86 C/m. a C b C c C d C e C 53. When grams of an unknown nonelectrolyte dissolves in 10.0 grams of water, the solution freezes at 2.16 C. What is the molecular weight of the unknown compound? K f for water = 1.86 C/m. a g/mol b. 116 g/mol c g/mol d g/mol

9 e. 132 g/mol

10 Chem 1100 Pre-Test 3 Answer Section MULTIPLE CHOICE 1. ANS: C PTS: 1 TOP: Pressure 2. ANS: D PTS: 1 TOP: Boyle's Law: The Volume-Pressure Relationship 3. ANS: E PTS: 1 TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale 4. ANS: C PTS: 1 TOP: The Combined Gas Law Equation 5. ANS: B PTS: 1 TOP: Avogadro's Law and the Standard Molar Volume 6. ANS: E PTS: 1 TOP: Avogadro's Law and the Standard Molar Volume 7. ANS: C PTS: 1 TOP: Summary of Gas Laws: The Ideal Gas Equation 8. ANS: B PTS: 1 TOP: Summary of Gas Laws: The Ideal Gas Equation 9. ANS: C PTS: 1 TOP: Dalton's Law of Partial Pressures 10. ANS: B PTS: 1 TOP: Dalton's Law of Partial Pressures 11. ANS: B PTS: 1 TOP: Dalton's Law of Partial Pressures 12. ANS: B PTS: 1 TOP: Dalton's Law of Partial Pressures 13. ANS: B PTS: 1 TOP: Mass-Volume Relationships in Reactions Involving Gases 14. ANS: E PTS: 1 DIF: Harder Question TOP: Mass-Volume Relationships in Reactions Involving Gases 15. ANS: E PTS: 1 TOP: Diffusion and Effusion of Gases 16. ANS: E PTS: 1 TOP: Deviations from Ideal Gas Behavior 17. ANS: A PTS: 1 TOP: The Kinetic-Molecular Theory 18. ANS: E PTS: 1 TOP: Deviations from Ideal Gas Behavior 19. ANS: C PTS: 1 DIF: Harder Question TOP: Deviations from Ideal Gas Behavior 20. ANS: B PTS: 1 TOP: Intermolecular Attractions and Phase Changes 21. ANS: D PTS: 1 TOP: Intermolecular Attractions and Phase Changes 22. ANS: C PTS: 1 TOP: Viscosity 23. ANS: B PTS: 1 TOP: Surface Tension 24. ANS: E PTS: 1 TOP: Boiling Points and Distillation 25. ANS: A PTS: 1 TOP: Heat Transfer Involving Liquids 26. ANS: C PTS: 1 TOP: Heat Transfer Involving Liquids 27. ANS: E PTS: 1 TOP: Heat Transfer Involving Liquids 28. ANS: B PTS: 1 TOP: Structures of Crystals 29. ANS: C PTS: 1 TOP: Bonding in Solids 30. ANS: D PTS: 1 TOP: Bonding in Solids 31. ANS: D PTS: 1 TOP: Bonding in Solids 32. ANS: C PTS: 1 DIF: Harder Question TOP: Bonding in Solids 33. ANS: E PTS: 1 TOP: Band Theory of Metals 34. ANS: D PTS: 1 TOP: Band Theory of Metals 35. ANS: A PTS: 1 TOP: Dissolution of Liquids in Liquids (Miscibility) 36. ANS: C PTS: 1 TOP: Rates of Dissolution and Saturation 37. ANS: C PTS: 1 TOP: Molality and Mole Fraction

11 38. ANS: C PTS: 1 TOP: Molality and Mole Fraction 39. ANS: D PTS: 1 TOP: Molality and Mole Fraction 40. ANS: B PTS: 1 TOP: Colligative Properties of Solutions 41. ANS: B PTS: 1 TOP: Lowering of Vapor Pressure and Raoult's Law 42. ANS: D PTS: 1 TOP: Lowering of Vapor Pressure and Raoult's Law 43. ANS: C PTS: 1 TOP: Boiling Point Elevation 44. ANS: A PTS: 1 TOP: Boiling Point Elevation 45. ANS: E PTS: 1 TOP: Freezing Point Depression 46. ANS: A PTS: 1 TOP: Osmotic Pressure 47. ANS: B PTS: 1 TOP: Molality and Mole Fraction 48. ANS: A PTS: 1 TOP: Molality and Mole Fraction 49. ANS: B PTS: 1 TOP: Molality and Mole Fraction 50. ANS: A PTS: 1 TOP: Colligative Properties of Solutions 51. ANS: C PTS: 1 TOP: Lowering of Vapor Pressure and Raoult's Law 52. ANS: D PTS: 1 TOP: Freezing Point Depression 53. ANS: D PTS: 1 TOP: Determination of Molecular Weight by Freezing Point Depression or Boiling Point Elevation

Chem 1100 Pre-Test 3. Multiple Choice Identify the choice that best completes the statement or answers the question.

Chem 1100 Pre-Test 3. Multiple Choice Identify the choice that best completes the statement or answers the question. Chem 1100 Pre-Test 3 Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Determine the oxidation number of the underlined element in K 2CO 3. a. 1 b. 2 c.