Chapter 5. Name: Class: Date: Multiple Choice Identify the choice that best completes the statement or answers the question.

Transcription

1 Class: Date: Chapter 5 Multiple Choice Identify the choice that best completes the statement or answers the question. 1. What is the pressure of the sample of gas trapped in the open-tube mercury manometer shown below if atmospheric pressure is 736 mmhg and h = 9.2 cm? A. 92 mmhg B. 644 mmhg C. 736 mmhg D. 828 mmhg 2. What will happen to the height (h) of the column of mercury in the manometer shown below if the stopcock is opened? A. h will decrease B. h will not change C. h will increase D. not enough information given to answer the question 1

2 3. A pressure that will support a column of Hg to a height of 256 mm would support a column of water to what height? The density of mercury is 13.6 g/cm 3 ; the density of water is 1.00 g/cm 3. A ft B. 348 cm C ft D cm 4. The pressure of a gas sample was measured to be 654 mmhg. What is the pressure in kpa? (1 atm = Pa) A kpa B. 118 kpa C kpa D kpa 5. A sample of pure oxygen gas has a pressure of 795 torr. What is the pressure of the oxygen in units of atmospheres? A atm B atm C atm D atm 6. Which of these properties is/are characteristic(s) of gases? A. High compressibility B. Relatively large distances between molecules C. Formation of homogeneous mixtures regardless of the nature of gases D. A, B, and C. 7. A sample of pure nitrogen has a temperature of 15 C. What is the temperature of the nitrogen in units of Kelvin? A. 300 K B. 290 K C. 288 K D K 8. Which of the following describes Dalton's Law? A. The pressure of a gas is proportional to its volume B. The total pressure of a gas mixture is the sum of the partial pressures of each gas in the mixture C. The temperature of a gas is proportional to its volume D. Only one variable can be changed from an initial state to a final state for a gas 9. Which of the following statements is consistent with Boyle's Law concerning an ideal gas? A. At constant temperature and moles, a plot of volume versus pressure is linear. B. At constant pressure and volume, a plot of temperature versus moles is linear. C. At constant pressure and moles, a plot of temperature versus volume is linear. D. At constant temperature and moles, a plot of pressure versus the inverse of volume is linear. 2

3 10. At constant temperature, the volume of the container that a sample of nitrogen gas is in is doubled. As a result the pressure of the nitrogen gas is halved. The amount of nitrogen gas is unchanged in this process. This is an example of: A. Boyle's Law B. Charles's Law C. Avogadro's Law D. Gay-Lussac's Law 11. At constant temperature and volume, a sample of oxygen gas is added to a sample of nitrogen gas. The pressure of the mixture is found by adding the pressures of the two individual gases. This is an example of: A. Boyle's Law B. Charles's Law C. Gay-Lussac's Law D. Dalton's Law 12. A sample of a gas occupies ml at 25 C and 760 mmhg. What volume will it occupy at the same temperature and 380 mmhg? A. 2,800 ml B. 2,100 ml C. 1,400 ml D. 1,050 ml 13. A sample of oxygen gas has a volume of 545 ml at 35 C. The gas is heated to 151 C at constant pressure in a container that can contract or expand. What is the final volume of the oxygen gas? A ml B. 396 ml C. 417 ml D. 267 ml 14. A 45 ml sample of nitrogen gas is cooled from 135 C to 15 C in a container that can contract or expand at constant pressure, what is the new volume of the nitrogen gas? A. 64 ml B. 5.0 ml C. 410 ml D. 32 ml 15. A sample of helium gas occupies 355mL at 23 C. If the container the He is in is expanded to 1.50 L at constant pressure, what is the final temperature for the He at this new volume? A. 1,250 C B. 978 C C C D C 16. The gas pressure in an aerosol can is 1.8 atm at 25 C. If the gas is an ideal gas, what pressure would develop in the can if it were heated to 475 C? A atm B atm C. 3.3 atm D. 4.5 atm 3

4 17. If the pressure of a gas sample is quadrupled and the absolute temperature is doubled, by what factor does the volume of the sample change? A. 8 B. 2 C. 1/2 D. 1/4 18. A small bubble rises from the bottom of a lake, where the temperature and pressure are 4 C and 3.0 atm, to the water's surface, where the temperature is 25 C and the pressure is 0.95 atm. Calculate the final volume of the bubble if its initial volume was 2.1 ml. A ml B. 6.2 ml C. 7.1 ml ml D ml 19. The temperature of a sample of argon gas in a 365 ml container at 740. mmhg and 25 C is lowered to 12 C. Assuming the volume of the container and the amount of gas is unchanged, calculate the new pressure of the argon. A atm B atm C atm D atm mole of hydrogen gas has a volume of 2.00 L at a certain temperature and pressure. What is the volume of mol of this gas at the same temperature and pressure? A L B L C L D L 21. At what temperature will a sample of nitrogen gas with a volume of 328 ml at 15 C and 748 mmhg occupy at a volume of L and a pressure of 642 mm Hg? Assume the amount of the nitrogen gas does not change. A. 676 C B. 404 C C. 396 C D. 274 C 22. Calculate the number of moles of gas contained in a 10.0 L tank at 22 C and 105 atm. (R = L atm/k mol) A mol B mol C mol D mol 4

5 23. Calculate the volume occupied by 35.2 g of methane gas (CH 4 ) at 25 C and 1.0 atm. R = L atm/k mol. A L B. 4.5 L C L D L 24. Calculate the volume occupied by 56.5 g of argon gas at STP. A L B L C L D. 1,270 L 25. Calculate the grams of SO 2 gas present at STP in a 5.9 L container. A g B g C. 15 g D. 17 g 26. Calculate the volume occupied by 25.2 g of CO 2 at 0.84 atm and 25 C. R = L atm/k mol. A L B L C L D L 27. A gas evolved during the fermentation of sugar was collected. After purification its volume was found to be 25.0 L at 22.5 C and 702 mmhg. How many moles of gas were collected? A mol B mol C mol D mol 28. How many atoms of He gas are present in a 450 ml container at 35 C and 740 mmhg? A He atoms B He atoms C. 1.2 x 10 5 He atoms D. 1.0 x He atoms 29. Calculate the mass, in grams, of 2.74 L of CO gas measured at 33 C and 945 mmhg. A g B g C g D g 30. A 250 ml flask contains 3.4 g of neon gas at 45 C. Calculate the pressure of the neon gas inside the flask. A atm B atm C. 18 atm D. 38 atm 5

6 31. Gases are sold in large cylinders for laboratory use. What pressure, in atmospheres, will be exerted by 2,500 g of oxygen gas (O 2 ) when stored at 22 C in a 40.0 L cylinder? A. 3.6 atm B. 10. atm C. 47 atm D. 1,500 atm 32. Calculate the density of CO 2 (g) at 120 C and 790 mmhg pressure. A g/l B. 1.4 g/l C. 1.8 g/l D. 3.4 g/l 33. Calculate the density of Br 2 (g) at 59.0 C and 1.00 atm pressure. A g/l B g/l C g/l D g/l 34. Calculate the density, in g/l, of chlorine (Cl 2 ) gas at STP. A g/l B g/l C g/l D g/l 35. Which of these gases will have the greatest density at the same specified temperature and pressure? A. H 2 B. CClF 3 C. CO 2 D. C 2 H Which one of these gases is "lighter-than-air"? A. Cl 2 B. Ne C. PH 3 D. NO Determine the molar mass of chloroform gas if a sample weighing g is collected in a flask with a volume of 102 cm 3 at 97 C. The pressure of the chloroform is 728 mmhg. A g/mol B g/mol C. 121g/mol D. 112 g/mol 38. What is the molar mass of Freon-11 gas if its density is 6.13 g/l at STP? A g/mol B g/mol C g/mol D. 137 g/mol 6

7 39. A g sample of an unknown vapor occupies 294 ml at 140. C and 847 mmhg. The empirical formula of the compound is CH 2. What is the molecular formula of the compound? A. CH 2 B. C 2 H 4 C. C 3 H 6 D. C 4 H A 1.17 g sample of an alkane hydrocarbon gas occupies a volume of 674 ml at 28 C and 741 mmhg. Alkanes are known to have the general formula CnH2n+2. What is the molecular formula of the gas in this sample? (R = L atm/k mol) A. CH 4 B. C 2 H 6 C. C 3 H 8 D. C 4 H A 1.07 g sample of a Noble gas occupies a volume of 363 ml at 35 C and 678 mmhg. Identify the Noble gas in this sample? (R = L atm/k mol) A. He B. Ne C. Ar D. Kr 42. A gaseous compound is 30.4% nitrogen and 69.6% oxygen by mass. A 5.25-g sample of the gas occupies a volume of 1.00 L and exerts a pressure of 1.26 atm at 4.0 C. Which of these choices is its molecular formula? A. NO B. NO 2 C. N 3 O 6 D. N 2 O A mixture of three gases has a total pressure of 1,380 mmhg at 298 K. The mixture is analyzed and is found to contain 1.27 mol CO 2, 3.04 mol CO, and 1.50 mol Ar. What is the partial pressure of Ar? A atm B. 301 mmhg C. 356 mmhg D. 5,345 mmhg 44. A sample of carbon monoxide gas was collected in a 2.0 L flask by displacing water at 28 C and 810 mmhg. Calculate the number of CO molecules in the flask. The vapor pressure of water at 28 C is 28.3 mmhg. A B C D

8 45. Air contains 78% N 2, 21% O 2, and 1% Ar, by volume. What is the density of air at 1,000. torr and 10 C? A g/l B. 1.0 g/l C. 1.3 g/l D. 1.8 g/l 46. What volume of sulfur dioxide gas at 45 C and 723 mmhg will react completely with L of oxygen gas at constant temperature and pressure? 2 SO 2 (g) + O 2 (g) 2SO 3 (g) A L B L C L D L L of gas A at 1.0 atm and 1.0 L of gas B at 1.0 atm are combined in a 3.0 L flask. The flask is sealed and over time they react to completely to give gas C according to the following chemical equation: 2A(g) + B(g) C(g) Assuming the temperature stays constant, what will be the pressure after the reaction goes to completion? A atm B atm C atm D atm 48. What volume of O 2 (g) at 810. mmhg pressure is required to react completely with a 4.50g sample of C(s) at 48 C? 2 C(s) + O 2 (g) 2 CO(g) A L B L C L D L 49. How many liters of chlorine gas at 25 C and atm can be produced by the reaction of 12.0 g of MnO 2 with excess HCl(aq) according to the following chemical equation? MnO 2 (s) + 4HCl(aq) MnCl 2 (aq) + 2H 2 O(l) + Cl 2 (g) A L B L C L D L 50. Calculate the volume of H 2 (g) at 273 K and 2.00 atm that will be formed when 275 ml of M HCl solution reacts with excess Mg to give hydrogen gas and aqueous magnesium chloride. A L B L C L D L 8

9 51. What mass of KClO 3 must be decomposed to produce 126 L of oxygen gas at 133 C and atm? (The other reaction product is solid KCl.) A g B g C. 272 g D. 408 g 52. Which statement is false? A. The average kinetic energies of molecules from samples of different "ideal" gases is the same at the same temperature. B. The molecules of an ideal gas are relatively far apart. C. All molecules of an ideal gas have the same kinetic energy at constant temperature. D. Molecules of a gas undergo many collisions with each other and the container walls. 53. The molecules of different samples of an ideal gas have the same average kinetic energies, at the same A. pressure. B. temperature. C. volume. D. density. 54. If equal masses of O 2 (g) and HBr(g) are in separate containers of equal volume and temperature, which one of these statements is true? A. The pressure in the O 2 container is greater than that in the HBr container. B. There are more HBr molecules than O 2 molecules. C. The average velocity of the O 2 molecules is less than that of the HBr molecules. D. The average kinetic energy of HBr molecules is greater than that of O 2 molecules. 55. Which gas has molecules with the greatest average molecular speed at 25 C? A. CH 4 B. Kr C. N 2 D. CO Which of these gas molecules have the highest average kinetic energy at 25 C? A. H 2 B. O 2 C. N 2 D. All the gases have the same average kinetic energy. 57. Deviations from the ideal gas law are greater at A. low temperatures and low pressures. B. low temperatures and high pressures. C. high temperatures and high pressures. D. high temperatures and low pressures. 9

10 58. Determine the pressure of the gas trapped in the apparatus shown below when the atmospheric pressure is 695 mmhg. A. 45 mmhg B. 650 mmhg C. 695 mmhg D. 740 mmhg g of hydrogen gas and 50.0 g of oxygen gas are introduced into an otherwise empty 9.00 L steel cylinder, and the hydrogen is ignited by an electric spark. If the reaction product is gaseous water and the temperature of the cylinder is maintained at 35 C, what is the final gas pressure inside the cylinder? A atm B atm C atm D atm g of gaseous ammonia and 6.50 g of oxygen gas are introduced into a previously evacuated 5.50 L vessel. If the ammonia and oxygen then react to yield NO gas and water vapor, what is the final density of the gas mixture inside the vessel at 23 C? A g/l B g/l C g/l D g/l 61. A method of removing CO 2 from a spacecraft is to allow the CO 2 to react with sodium hydroxide. (The products of the reaction are sodium carbonate and water.) What volume of carbon dioxide at 25 C and 749 mmhg can be removed per kilogram of sodium hydroxide that reacts? A. 276 L B. 284 L C. 301 L D. 310 L 10

11 62. A spacecraft is filled with atm of N 2 and atm of O 2. Suppose a micrometeor strikes this spacecraft and puts a very small hole in it's side. Under these circumstances, A. O 2 is lost from the craft 6.9% faster than N 2 is lost. B. O 2 is lost from the craft 14% faster than N 2 is lost. C. N 2 is lost from the craft 6.9% faster than O 2 is lost. D. N 2 is lost from the craft 14% faster than O 2 is lost atm of dry nitrogen, placed in a container having a pinhole opening in its side, leaks from the container 3.55 times faster than does atm of an unknown gas placed in this same apparatus. Which of these species could be the unknown gas? A. NH 3 B. C 4 H 10 C. SF 6 D. UF Samples of the following volatile liquids are opened simultaneously at one end of a room. If you are standing at the opposite end of this room, which species would you smell first? (Assume that your nose is equally sensitive to all these species.) A. ethyl acetate (CH 3 COOC 2 H 5 ) B. camphor (C 10 H 16 O) C. naphthalene (C 10 H 8 ) D. diethyl ether (C 2 H 5 OC 2 H 5 ) 65. A sample of mercury(ii) oxide is placed in a 5.00 L evacuated container and heated until it decomposes entirely to mercury metal and oxygen gas. The container is then cooled to 25 C. One now finds that the gas pressure inside the container is 1.73 atm. What mass of mercury(ii) oxide was originally placed into the container? A g B. 153g C g D. 913 g 66. The mole fraction of oxygen molecules in dry air is What volume of dry air at 1.00 atm and 25 C is required for burning 1.00 L of hexane (C 6 H 14, density = g/ml) completely, yielding carbon dioxide and water? A L B. 712 L C. 894 L D L 67. A block of dry ice (solid CO 2, density = 1.56 g/ml) of dimensions 25.0 cm 25.0 cm 25.0 cm is left to sublime (i.e. to pass from the solid phase to the gas phase) in a closed chamber of dimensions 4.00 m 5.00 m 3.00 m. The partial pressure of carbon dioxide in this chamber at 25 C will be A mmhg B mmhg C. 171 mmhg D mmhg 11

12 68. A 2.50-L flask contains a mixture of methane (CH 4 ) and propane (C 3 H 8 ) at a pressure of 1.45 atm and 20 C. When this gas mixture is then burned in excess oxygen, 8.60 g of carbon dioxide is formed. (The other product is water.) What is the mole fraction of methane in the original gas mixture? A B C D

13 Chapter 5 Answer Section MULTIPLE CHOICE 1. ANS: B PTS: 1 DIF: Medium REF: Section: ANS: A PTS: 1 DIF: Medium REF: Section: ANS: B PTS: 1 DIF: Medium REF: Section: ANS: A PTS: 1 DIF: Medium REF: Section: ANS: B PTS: 1 DIF: Medium REF: Section: ANS: D PTS: 1 DIF: Easy REF: Section: ANS: C PTS: 1 DIF: Easy REF: Section: ANS: B PTS: 1 DIF: Easy REF: Section: ANS: D PTS: 1 DIF: Easy REF: Section: ANS: A PTS: 1 DIF: Easy REF: Section: ANS: D PTS: 1 DIF: Easy REF: Section: ANS: A PTS: 1 DIF: Medium REF: Section: ANS: A PTS: 1 DIF: Medium REF: Section: ANS: D PTS: 1 DIF: Medium REF: Section: ANS: B PTS: 1 DIF: Medium REF: Section: ANS: D PTS: 1 DIF: Medium REF: Section: ANS: C PTS: 1 DIF: Medium REF: Section: ANS: C PTS: 1 DIF: Medium REF: Section: ANS: B PTS: 1 DIF: Medium REF: Section: ANS: C PTS: 1 DIF: Medium REF: Section: ANS: B PTS: 1 DIF: Medium REF: Section: 5.4 1

14 22. ANS: D PTS: 1 DIF: Medium REF: Section: ANS: C PTS: 1 DIF: Medium REF: Section: ANS: B PTS: 1 DIF: Medium REF: Section: ANS: D PTS: 1 DIF: Medium REF: Section: ANS: C PTS: 1 DIF: Medium REF: Section: ANS: A PTS: 1 DIF: Medium REF: Section: ANS: D PTS: 1 DIF: Medium REF: Section: ANS: C PTS: 1 DIF: Medium REF: Section: ANS: C PTS: 1 DIF: Medium REF: Section: ANS: B PTS: 1 DIF: Medium REF: Section: ANS: B PTS: 1 DIF: Medium REF: Section: ANS: B PTS: 1 DIF: Medium REF: Section: ANS: C PTS: 1 DIF: Medium REF: Section: ANS: B PTS: 1 DIF: Medium REF: Section: ANS: B PTS: 1 DIF: Medium REF: Section: ANS: B PTS: 1 DIF: Medium REF: Section: ANS: D PTS: 1 DIF: Medium REF: Section: ANS: B PTS: 1 DIF: Medium REF: Section: ANS: C PTS: 1 DIF: Medium REF: Section: ANS: D PTS: 1 DIF: Medium REF: Section: ANS: D PTS: 1 DIF: Medium REF: Section: ANS: C PTS: 1 DIF: Medium REF: Section: ANS: A PTS: 1 DIF: Medium REF: Section: ANS: D PTS: 1 DIF: Difficult REF: Section: 5.6 2

15 46. ANS: D PTS: 1 DIF: Medium REF: Section: ANS: A PTS: 1 DIF: Medium REF: Section: ANS: C PTS: 1 DIF: Medium REF: Section: ANS: B PTS: 1 DIF: Medium REF: Section: ANS: B PTS: 1 DIF: Difficult REF: Section: ANS: C PTS: 1 DIF: Difficult REF: Section: ANS: C PTS: 1 DIF: Medium REF: Section: ANS: B PTS: 1 DIF: Easy REF: Section: ANS: A PTS: 1 DIF: Medium REF: Section: ANS: A PTS: 1 DIF: Easy REF: Section: ANS: D PTS: 1 DIF: Easy REF: Section: ANS: B PTS: 1 DIF: Medium REF: Section: ANS: D PTS: 1 DIF: Medium REF: Section: ANS: D PTS: 1 DIF: Difficult REF: Section: ANS: D PTS: 1 DIF: Difficult REF: Section: ANS: D PTS: 1 DIF: Difficult REF: Section: ANS: C PTS: 1 DIF: Medium REF: Section: ANS: D PTS: 1 DIF: Medium REF: Section: ANS: D PTS: 1 DIF: Medium REF: Section: ANS: B PTS: 1 DIF: Difficult REF: Section: ANS: A PTS: 1 DIF: Difficult REF: Section: ANS: C PTS: 1 DIF: Medium REF: Section: ANS: D PTS: 1 DIF: Difficult REF: Section: 5.6 3