Chemistry Chapter 11 Test Review

Transcription

1 Chemistry Chapter 11 Test Review Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Pressure is the force per unit a. volume. c. length. b. surface area. d. depth. 2. What is the SI unit of force? a. torr c. pound b. pascal d. newton 3. What does the constant bombardment of gas molecules against the inside walls of a container produce? a. temperature c. pressure b. density d. diffusion 4. Why does a can collapse when a vacuum pump removes air from the can? a. The inside and outside forces balance out and crush the can. b. The unbalanced outside force from atmospheric pressure crushes the can. c. The atmosphere exerts pressure on the inside of the can and crushes it. d. The vacuum pump creates a force that crushes the can. 5. If the height of mercury in a barometer at 0 C is less than 760 mm Hg, then a. the atmospheric pressure is less than standard atmospheric pressure. b. the atmospheric pressure is greater than standard atmospheric pressure. c. the atmospheric pressure is equal to standard atmospheric pressure. d. the atmospheric pressure cannot be determined. 6. A pressure of 745 mm Hg equals a. 745 torr. c. 1 pascal. b. 1 torr. d. 745 pascal. 7. Convert the pressure 0.75 atm to mm Hg. a mm Hg c. 570 mm Hg b. 430 mm Hg d. 760 mm Hg 8. Convert the pressure atm to mm Hg. a. 365 mm Hg c. 638 mm Hg b. 437 mm Hg d. 780 mm Hg 9. Convert the pressure 2.50 atm to kpa. a. 1 kpa c. 760 kpa b. 253 kpa d kpa 10. Convert the pressure 1.30 atm to kpa. a. 2 kpa c. 132 kpa b. 115 kpa d. 245 kpa 11. Standard temperature is exactly a. 100 C. c. 0 C. b. 273 C. d. 0 K.

2 12. Standard pressure is exactly a. 1 atm. c atm. b. 760 atm. d. 101 atm. 13. To correct for the partial pressure of water vapor in a gas collection bottle, the vapor pressure of H 2 O at the collecting temperature is generally a. subtracted from the partial pressure of the collected gas. b. added to the pressure of the collected gas. c. subtracted from the atmospheric pressure. d. added to the atmospheric pressure. 14. A mixture of four gases exerts a total pressure of 860 mm Hg. Gases A and B each exert 220 mm Hg. Gas C exerts 110 mm Hg. What pressure is exerted by gas D? a. 165 mm Hg c. 860 mm Hg b. 310 mm Hg d. 220 mm Hg Use the table below to answer the following questions. Water Vapor Pressure Temperature ( C) Pressure (mm Hg) What is the partial pressure of water vapor at 10 C and 750 mm Hg? a. 9.2 mm Hg c. 6.5 mm Hg b mm Hg d mm Hg 16. A sample of gas is collected by water displacement at mm Hg and 30 C. What is the partial pressure of the gas? a mm Hg c. 630 mm Hg b mm Hg d mm Hg 17. The volume of a gas is ml when the pressure is 1.00 atm. At the same temperature, what is the pressure at which the volume of the gas is 2.0 L? a. 0.5 atm c atm b. 5.0 atm d. 800 atm 18. A sample of oxygen occupies 560. ml when the pressure is mm Hg. At constant temperature, what volume does the gas occupy when the pressure decreases to mm Hg? a ml c ml b ml d ml 19. If the temperature of a fixed quantity of gas decreases and the pressure remains unchanged,

3 a. its volume increases. c. its volume decreases. b. its volume is unchanged. d. its density decreases. 20. At 7.0 C, the volume of a gas is 49 ml. At the same pressure, its volume is 74 ml at what temperature? a. 3.0 C c. 120 C b. 423 C d. 150 C 21. The volume of a gas is 93 ml when the temperature is 91 C. If the temperature is reduced to 0 C without changing the pressure, what is the new volume of the gas? a. 70. ml c. 120 ml b. 93 ml d. 273 ml 22. If the temperature of a fixed quantity and volume of gas changes, what also changes? a. pressure c. mass b. density d. formula 23. Why does the air pressure inside the tires of a car increase when the car is driven? a. Some of the air has leaked out. b. The air particles collide with the tire after the car is in motion. c. The air particles inside the tire increase their speed because their temperature rises. d. The atmosphere compresses the tire. 24. On a cold winter morning when the temperature is 13 C, the air pressure in an automobile tire is 1.5 atm. If the volume does not change, what is the pressure after the tire has warmed to 15 C? a. 1.5 atm c. 3.0 atm b. 1.7 atm d atm 25. The pressure of a sample of gas at 10.0 C increases from 700. mm Hg to 900. mm Hg. What is the new temperature? a. 0 C c C b. 364 C d C 26. The volume of a sample of oxygen is ml when the pressure is 1.00 atm and the temperature is 27.0 C. At what temperature is the volume 1.00 L and the pressure atm? a C c K b C d. 227 C 27. The volume of a gas collected when the temperature is 11.0 C and the pressure is 710 mm Hg measures 14.8 ml. What is the calculated volume of the gas at 20.0 C and 740 mm Hg? a. 7.8 ml c ml b ml d. 15 ml 28. If 0.5 L of O 2 (g) reacts with H 2 to produce 1 L of H 2 O(g), what is the volume of H 2 O(g) obtained from 1 L of O 2 (g)? a. 0.5 L c. 2 L b. 1.5 L d. 2.5 L 29. For reactants or products that are gases, the coefficients in the chemical equation indicate a. the number of grams of each substance. b. volume. c. molar volume. d. density.

4 30. The equation for the production of methane is C + 2H 2 (g) needed to produce 20. L of methane? a. 2.0 L c L b. 20. L d. 40. L CH 4 (g). How many liters of hydrogen are 31. What is the number of moles of H 2 produced when 23 g of sodium react with water according to the equation 2Na(s) + 2H 2 O(l) 2NaOH(aq) + H 2 (g)? a mol c. 2.0 mol b. 1.0 mol d. 4.0 mol 32. If the pressure and temperature of a gas are held constant and some gas is added to the container or some is allowed to escape, a change is which of the following can be observed? a. kinetic energy c. rate of diffusion b. volume d. chemical properties 33. If the temperature of a container of gas remains constant, how could the pressure of the gas increase? a. The mass of the gas molecules increase. b. The diffusion of the gas molecules increases. c. The size of the container increases. d. The number of gas molecules in the container increases. 34. Equal volumes of diatomic gases under the same conditions of temperature and pressure contain the same number of a. protons. c. molecules. b. ions. d. electrons. 35. If gas A has a molar mass greater than that of gas B and samples of each gas at identical temperatures and pressures contain equal numbers of molecules, then a. the volumes of gas A and gas B are equal. b. the volume of gas A is greater than that of gas B. c. the volume of gas B is greater than that of gas A. d. their volumes are proportional to their molar masses. 36. At constant temperature and pressure, gas volume is directly proportional to the a. molar mass of the gas. c. density of the gas at STP. b. number of moles of gas. d. rate of diffusion. 37. In the expression V = kn, n represents a. the ideal gas constant. c. the number of moles of gas. b. Avogadro's number. d. a constant. 38. According to Avogadro's law, 1 L of H 2 (g) and 1 L of O 2 (g) at the same temperature and pressure a. have the same mass. b. have unequal volumes. c. contain 1 mol of gas each. d. contain equal numbers of molecules. 39. The gas pressure inside a container decreases when a. the number of gas molecules is increased. b. the number of gas molecules is decreased. c. the temperature is increased. d. the number of molecules is increased and the temperature is increased.

5 40. The standard molar volume of a gas at STP is a L. c. g-mol wt/22.4 L. b. g/22.4 L. d. 1 L. 41. At STP, the standard molar volume of a gas of known volume can be used to calculate the a. number of moles of gas. c. gram-molecular weight. b. rate of diffusion. d. gram-molecular volume. 42. Chlorine is produced by the reaction 2HCl(g) H 2 (g) + Cl 2 (g). How many grams of HCl (36.5 g/mol) must be used to produce 10.0 L of chlorine at STP? a g c g b g d g 43. Iron(IV) oxide, FeO 2, is produced by the reaction Fe + O 2 FeO 2 (87.8 g/mol). How many grams of FeO 2 can be produced from 50.0 L of O 2 at STP? a g c. 50 g b g d g 44. All of the following equations are statements of the ideal gas law except a. P = nrtv. c.. b When pressure, volume, and temperature are known, the ideal gas law can be used to calculate a. the chemical formula. c. molar amount. b. the ideal gas constant. d. rate of effusion. 46. Calculate the approximate volume of a mol sample of gas at 15.0 C and a pressure of 1.10 atm. a L c L b L d. 139 L 47. Calculate the approximate temperature of a 0.50 mol sample of gas at 750 mm Hg and a volume of 12 L. a. 7 C c. 15 C b. 11 C d. 288 C 48. What is the pressure exerted by 1.2 mol of a gas with a temperature of 20. C and a volume of 9.5 L? a atm c. 3.0 atm b. 1.0 atm d. 30. atm d. 49. A sample of gas at 25 C has a volume of 11 L and exerts a pressure of 660 mm Hg. How many moles of gas are in the sample? a mol c. 9.3 mol b. 3.9 mol d. 87 mol 50. A gas sample with a mass of 12.8 g exerts a pressure of 1.2 atm at 15 C and a volume of 3.94 L. What is the molar mass of the gas? a. 19 g/mol c. 64 g/mol b. 32 g/mol d. 128 g/mol 51. If a gas with an odor is released in a room, it can quickly be detected across the room because it a. diffuses. c. is compressed. b. is dense. d. condenses..

6 52. Which is an example of effusion? a. air slowly escaping from a pinhole in a tire b. the aroma of a cooling pie spreading across a room c. helium dispersing into a room after a balloon pops d. oxygen and gasoline fumes mixing in an automobile carburetor 53. What is the process by which molecules of a gas randomly encounter and pass through a small opening in a container? a. diffusion c. distillation b. vaporization d. effusion 54. What determines the average kinetic energy of the molecules of any gas? a. temperature c. temperature and pressure b. pressure d. molar mass 55. According to Graham's law, two gases at the same temperature and pressure will have different rates of effusion because they have different a. volumes. c. kinetic energies. b. molar masses. d. condensation points. 56. Suppose that two gases with unequal molar masses were injected into opposite ends of a long tube at the same time and allowed to diffuse toward the center. They should begin to mix a. in approximately five minutes. b. closer to the end that held the heavier gas. c. closer to the end that held the lighter gas. d. exactly in the middle. Use the table below to answer the following questions. Element Atomic Mass Argon Bromine Carbon Chlorine Fluorine Helium Hydrogen Nitrogen Oxygen How many times greater is the rate of effusion of molecular fluorine than that of molecular bromine at the same temperature and pressure? a c b d How many times greater is the rate of effusion of oxygen gas than that of carbon dioxide gas at the same temperature and pressure? a c b d

7 59. A sample of helium diffuses 4.57 times faster than an unknown gas diffuses. What is the molar mass of the unknown gas? a. 12 g/mol c g/mol b g/mol d g/mol Short Answer 1. Why do your ears "pop" in an airplane? Problem Use the table below to answer the following questions. Element Atomic Mass Argon Bromine Carbon Chlorine Fluorine Helium Hydrogen Nitrogen Oxygen A gas sprayed from an aerosol can effuse 2.08 times slower than nitrogen diffuses. What is the molar mass of the unknown gas? 2. A steam vent releases an unknown gas along with steam. This gas travels 1.56 times as slowly as the steam. What is the molar mass of the unknown gas?