Please do not write on this test. Please use the answer sheet.

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1 AP Chemistry Test (Chapter 5) Multiple Choice (50%) Please do not write on this test. Please use the answer sheet. Form: Snowboard 1) A sample of argon gas is sealed in a rigid metal tank. The temperature of the tank is halved. What has happened to the pressure inside the tank? A) It is halved. B) It is reduced by 1/4 th. C) It is doubled. D) It increases by 4. E) It cannot be predicted. 2) Please choose all postulates of the kinetic molecular theory. I) Gas particles exhibit attractions for each other. II) Two gases mix homogenously to fill their container. III) Collisions between gas particles are inelastic. IV) Gas particles are in constant, random motion. V) The volume of the actual gas particles in a container is small compared to the volume of the container. A) I, II, III, IV B) I, II, IV, V C) II, IV D) II, IV, V E) None of these are correct. 3) Two metal tanks have the same volume and temperature. One contains 32 g oxygen and the other contains 80 g argon. Which one is a true statement? A) The density of oxygen gas is greater than the density of the argon gas. B) The particles in the argon tank have a greater kinetic energy than the particles in the oxygen tank. C) The argon tank has twice as many representative particles. D) The pressure is greater in the oxygen tank. 4) At an underwater depth of 250 ft, the pressure is 8.38 atm. What should the mol% of O 2 be in the diving gas for the partial pressure of the O 2 in the mixture to be 0.21 atm, which is the same as in air at the surface? A) 21% B) 1.7% C) 2.5% D) 17% E) None of these 5) What is the density of butene gas at STP? A) 2.42 g/l B) 2.53 g/l C) 1.97 g/l D) 2.32 g/l E) None of these 6) Which gas deviates the least from ideal gas behavior. A) O 2 B) CH 4 C) F 2 D) H 2 O E) NH 3

2 7) A glass flask is filled at room temperature with an equal number of moles of O 2, He and CO 2 gases. The gases slowly leak out through a pinhole leak in the cork of the flask. After some of the gas has effused, which one is true of the partial pressures of the gases remaining in the flask? A) He > O 2 > CO 2 B) O 2 > He > CO 2 C) CO 2 > He > O 2 D) CO 2 = He = O 2 E) CO 2 > O 2 > He 8) Which of the following best explains why a hot air balloon rises? A) The heat decreases the volume of the balloon; thus increasing its density. B) The heat decreases the volume of the balloon; thus decreasing its density. C) The heat increases the volume of the balloon; thus increasing its density. D) The heat increases the volume of the balloon; thus decreasing its density. 9) Which of the following conditions would be most likely to cause a gas to deviate most from ideal behavior? I. Low external pressure II. High temperature III. Large volume IV. Nonpolar molecules V. Intermolecular attractions A) I, III, IV, V B) I, II, III C) IV, V D) I, II, IV E) None of these are correct 10) N 2 gas was collected over water at 54 o C. If the vapor pressure of water at 54 o C is 61 mm Hg and the atmospheric pressure is 762 mm Hg, what is the partial pressure of the N 2 gas? A) 823 mm Hg B) 708 mm Hg C) 762 mm Hg D) 738 mm Hg E) 701 mm Hg 11) An air sample is confined to a rigid syringe. Which one will occur if the plunger on the syringe is compressed? I) Water vapor in the air could condense. II) The pressure of the air in the syringe will increase. III) The volume of the syringe will decrease. IV) The temperature of the air will increase. V) The density of the air will decrease. A) I, II, III, IV B) II, III C) III, IV, V D) I, II, III, E) None of these will occur.

3 12) A sealed container contains 0.20 mol O 2 gas and 0.10 mol H 2 gas. If the temperature is 25 o C in the container, which one is true? A) The partial pressures of the two gases are the same. B) The average kinetic energies of the two gases are the same. C) The molecular masses of the two gases are the same. D) The total masses of the two gases are the same. E) The average molecular velocities of the two gases are the same. 13) What is the pressure in this stoppered flask if the atmospheric pressure is 763 mm Hg? 28 mm Hg A) 785 mm Hg B) 791 mm Hg C) 772 mm Hg D) 735 mm Hg E) None of these 14) A 3.5-L balloon is tied outside to a fence as the weather changes. Which of the following weather systems will cause the balloon to expand to 3.6 L? A) Low pressure and high temperature B) Low pressure and low temperature C) High pressure and low temperature D) High pressure and high temperature 15) Which one is true? A) As the temperature of water increases, its vapor pressure increases because more B) As the temperature of water increases, its vapor pressure decreases because more C) As the temperature of water increases, its vapor pressure increases because less D) As the temperature of water increases, its vapor pressure decreases because less 16) Which one is true? A) Some gases exist at 0 K. B) Only gases exist at 0 o C C) Some liquids exist at 0 o C. D) Only solids exist at 0 o C. E) Some liquids exist at 0 K.

4 17) Which one illustrates the correct relationship? A) High altitude = more air = more pressure = lower boiling point B) High altitude = more air = less pressure = lower boiling point C) High altitude = less air = more pressure = higher boiling point D) High altitude = less air = less pressure = higher boiling point E) High altitude = less air = less pressure = lower boiling point 18) Which one is false about the Coke can demonstration? A) A vacuum forms when the water vapor pushes out the steam from the can. B) The can is filled with empty space after the water vapor condenses. C) Atmospheric pressure fills the vacuum with water as it implodes the can. D) The can is initially full of air at approximately 1 atm. E) A vacuum forms when the water vapor condenses. 19) Which one causes the bends? A) Decreased external pressure causes decreased solubility of gas in your blood. B) Increased external pressure causes decreased solubility of gas in your blood. C) Decreased external pressure causes increased solubility of gas in your blood. D) Increased external pressure causes increased solubility of gas in your blood. 20) If you flew to a planet with an atmospheric pressure of 2 atm, which one would be the most likely? A) Boiling hot chocolate is cooler than on Earth. B) Sprite bottled on Earth fizzes more when it is opened on the planet. C) Your ear drums painfully implode. D) A bag of potato chips packaged on Earth appears to have a larger volume on the planet. E) You experience the bends. 21) If you pack a sealed bottle of suntan lotion in your suitcase in Houston (sea level) & then fly to Colorado for a fun-filled ski trip, which one are you likely to observe when you arrive at the ski resort? A) The bottle will bulge inward and lotion will squirt out when you open it. B) The bottle will bulge inward and air will rush in when you open it. C) The bottle will bulge outward and lotion will squirt out when you open it. D) The bottle will bulge outward and air will rush in when you open it.

5 22) Why do wild llamas living in the high mountains of Peru contain very specialized hemoglobin? A) Low partial pressure of O 2 in the atmosphere coupled with increased solubility of O 2 B) Low partial pressure of O 2 in the atmosphere coupled with decreased solubility of O 2 C) High partial pressure of O 2 in the atmosphere coupled with increased solubility of O 2 D) High partial pressure of O 2 in the atmosphere coupled with decreased solubility of O 2 23) A beaker of water at room temperature (22 o C) is placed into a small, closed environment where the atmospheric pressure is 0 atm. Which one will occur? A) The water will begin to boil when the vapor pressure increases. B) The water will boil until all the water has vaporized & the beaker is empty. C) The water molecules will not have enough kinetic energy to vaporize. D) The water will boil until the vapor pressure prevents the liquid from boiling further. E) The water will only boil when heat is added to it. 24) Please choose all correctly paired examples. I) Graham s Law: A flatulent diffuses through the air. II) Dalton s Law: Atmospheric pressure is the sum of the partial pressures of individual gases. III) Charles s Law: Bubbles of gas exhaled at the bottom of a pool expand as they rise to the surface. IV) Gay-Lussac s Law: Bubbles of gas expand as you bake yeast bread. V) Henry s Law: A soda fizzes more at higher altitudes. A) I, II, IV B) I, V C) I, II, V D) IV, V E) None of these are correct. 25) Thermal pollution occurs when the temperature of a lake or river increases by 1-2 o C. Why does this slight temperature increase cause fish death? A) The temperature increase causes increased kinetic energy of O 2 which decreases its B) The temperature increase causes increased kinetic energy of O 2 which increases its C) The temperature increase causes decreased kinetic energy of O 2 which decreases its D) The temperature increase causes decreased kinetic energy of O 2 which increases its

6 Problems (60%) Please show all your work for any credit. 1) A g sample of impure Mn 2 (CO 3 ) 5 is decomposed with heat ml CO 2 is collected over water at a temperature of o C. The gas is collected at an atmospheric pressure of 773 torr. Water has a vapor pressure of 79 torr at o C. What is the % Mn 2 (CO 3 ) 3 in the original impure sample? Mn 2 (CO 3 ) 3 Mn 2 O CO 2 2) 2 C 2 H 6 (g) + 2 NH 3 (g) + 3 O 2 (g) 2 C 3 H 3 N (g) + 6 H 2 O (g) What will the partial pressure of C 3 H 3 N be when g O 2 reacts with excess ethane and ammonia in a stoppered ml flask at o C? Please assume the temperature doesn t change during the reaction. 3) What is the molar mass of the dry gas collected in this 100-mL eudiometer (gas collection tube)? Mass of Eudiometer Mass of Eudiometer + Gas Volume of Gas in Eudiometer Temperature of Gas in Flask Barometric Pressure of Gas g g ml 88.0 o C 899 torr 4) What is the total pressure in this flask after the stopcock is opened & the gases are allowed to mix at a constant temperature? 2.82 L N L O atm 0.87 atm 5) A sample of gas has a volume of 1.25 L when the pressure on it is 15.0 atm at a temperature of o C. What temperature will it have when the pressure increases to 16.0 atm and the volume increases to 1.30 L? 6) A gas has an empirical formula of C 3 H 7. The gas has a density of g/l at STP. What is the molecular formula?

7 7) Air bags are activated when a severe impact causes a steel ball to compress a spring and electrically ignite a detonator cap. This causes sodium azide to decompose explosively according to the following reaction: 2 NaN 3 (s) 2 Na (s) + 3 N 2 (g) What volume will the air bag occupy if the bag is packed with g NaN 3 (s) when the air temperature inside the car is 22.0 o C and the atmospheric pressure is 755 mm Hg? 8) A Ziploc bag has a volume of 2877 ml. The atmospheric pressure is 768 mm Hg & the air temperature is 19.5 o C. What mass of CaCO 3 and volume of 1.22 M HCl are necessary in the bag to completely fill it with CO 2? Ignore the HCl volume and negligible H 2 O that occupy space in the Ziploc bag. CaCO 3 (s) + 2 HCl (aq) CaCl 2 (aq) + H 2 O (l) + CO 2 (g) Please use the following information to answer questions In experiment #1, a g sample of an organic compound composed entirely of carbon, hydrogen and oxygen was burned to produce g CO 2 and g H 2 O. Assume complete combustion. 9) What is the empirical formula of this gaseous hydrocarbon? 10) In experiment #2, a different g sample of the gaseous hydrocarbon is analyzed. It occupies L at 238 o C and 808 mm Hg. What is the molecular formula of this gaseous hydrocarbon?

8 AP Chemistry Test (Chapter 5) Multiple Choice (50%) Please do not write on this test. Please use the answer sheet. Form: Snow Skis 1) A sample of argon gas is sealed in a rigid metal tank. The temperature of the tank is halved. What has happened to the pressure inside the tank? A) It is doubled. B) It is reduced by 1/4 th. C) It is halved. D) It increases by 4. E) It cannot be predicted. 2) Please choose all postulates of the kinetic molecular theory. I) Gas particles exhibit attractions for each other. II) Two gases mix homogenously to fill their container. III) Collisions between gas particles are inelastic. IV) Gas particles are in constant, random motion. V) The volume of the actual gas particles in a container is small compared to the volume of the container. A) II, IV B) II, IV, V C) I, II, III, IV D) I, II, IV, V E) None of these are correct. 3) Two metal tanks have the same volume and temperature. One contains 32 g oxygen and the other contains 80 g argon. Which one is a true statement? A) The density of oxygen gas is greater than the density of the argon gas. B) The pressure is greater in the oxygen tank. C) The argon tank has twice as many representative particles. D) The particles in the argon tank have a greater kinetic energy than the particles in the oxygen tank. 4) At an underwater depth of 250 ft, the pressure is 8.38 atm. What should the mol% of O 2 be in the diving gas for the partial pressure of the O 2 in the mixture to be 0.21 atm, which is the same as in air at the surface? A) 1.7% B) 21% C) 17% D) 2.5% E) None of these 5) What is the density of butene gas at STP? A) 2.32 g/l B) 1.97 g/l C) 2.53 g/l D) 2.42 g/l E) None of these 6) Which gas deviates the least from ideal gas behavior. A) O 2 B) F 2 C) CH 4 D) H 2 O E) NH 3

9 7) A glass flask is filled at room temperature with an equal number of moles of O 2, He and CO 2 gases. The gases slowly leak out through a pinhole leak in the cork of the flask. After some of the gas has effused, which one is true of the partial pressures of the gases remaining in the flask? A) He > O 2 > CO 2 B) CO 2 > O 2 > He C) CO 2 > He > O 2 D) CO 2 = He = O 2 E) O 2 > He > CO 2 8) Which of the following best explains why a hot air balloon rises? A) The heat decreases the volume of the balloon; thus increasing its density. B) The heat decreases the volume of the balloon; thus decreasing its density. C) The heat increases the volume of the balloon; thus increasing its density. D) The heat increases the volume of the balloon; thus decreasing its density. 9) Which of the following conditions would be most likely to cause a gas to deviate most from ideal behavior? I) Low external pressure II) High temperature III) Large volume IV) Nonpolar molecules V) Intermolecular attractions A) IV, V B) I, II, III C) I, III, IV, V D) I, II, IV E) None of these are correct 10) N 2 gas was collected over water at 54 o C. If the vapor pressure of water at 54 o C is 61 mm Hg and the atmospheric pressure is 762 mm Hg, what is the partial pressure of the N 2 gas? A) 823 mm Hg B) 708 mm Hg C) 762 mm Hg D) 738 mm Hg E) 701 mm Hg 11) An air sample is confined to a rigid syringe. Which one will occur if the plunger on the syringe is compressed? I) Water vapor in the air could condense. II) The pressure of the air in the syringe will increase. III) The volume of the syringe will decrease. IV) The temperature of the air will increase. V) The density of the air will decrease. A) I, II, III B) II, III C) III, IV, V D) I, II, III, IV E) None of these will occur.

10 12) A sealed container contains 0.20 mol O 2 gas and 0.10 mol H 2 gas. If the temperature is 25 o C in the container, which one is true? A) The partial pressures of the two gases are the same. B) The molecular masses of the two gases are the same. C) The average kinetic energies of the two gases are the same. D) The total masses of the two gases are the same. E) The average molecular velocities of the two gases are the same. 13) What is the pressure in this stoppered flask if the atmospheric pressure is 763 mm Hg? 28 mm Hg A) 772 mm Hg B) 735 mm Hg C) 785 mm Hg D) 791 mm Hg E) None of these 14) A 3.5-L balloon is tied outside to a fence as the weather changes. Which of the following weather systems will cause the balloon to expand to 3.6 L? A) Low pressure and low temperature B) Low pressure and high temperature C) High pressure and high temperature D) High pressure and low temperature 15) Which one is true? A) As the temperature of water increases, its vapor pressure increases because more B) As the temperature of water increases, its vapor pressure decreases because more C) As the temperature of water increases, its vapor pressure increases because less D) As the temperature of water increases, its vapor pressure decreases because less 16) Which one is true? A) Some liquids exist at 0 o C. B) Only gases exist at 0 o C C) Some gases exist at 0 K. D) Only solids exist at 0 o C. E) Some liquids exist at 0 K.

11 17) Which one illustrates the correct relationship? A) High altitude = more air = more pressure = lower boiling point B) High altitude = more air = less pressure = lower boiling point C) High altitude = less air = more pressure = higher boiling point D) High altitude = less air = less pressure = lower boiling point E) High altitude = less air = less pressure = higher boiling point 18) Which one is false about the Coke can demonstration? A) A vacuum forms when the water vapor pushes out the steam from the can. B) The can is filled with empty space after the water vapor condenses. C) Atmospheric pressure fills the vacuum with water as it implodes the can. D) The can is initially full of air at approximately 1 atm. E) A vacuum forms when the water vapor condenses. 19) Which one causes the bends? A) Decreased external pressure causes decreased solubility of gas in your blood. B) Increased external pressure causes decreased solubility of gas in your blood. C) Decreased external pressure causes increased solubility of gas in your blood. D) Increased external pressure causes increased solubility of gas in your blood. 20) If you flew to a planet with an atmospheric pressure of 2 atm, which one would be the most likely? A) Boiling hot chocolate is cooler than on Earth. B) Sprite bottled on Earth fizzes more when it is opened on the planet. C) You experience the bends. D) A bag of potato chips packaged on Earth appears to have a larger volume on the planet. E) Your ear drums painfully implode. 21) If you pack a sealed bottle of suntan lotion in your suitcase in Houston (sea level) & then fly to Colorado for a fun-filled ski trip, which one are you likely to observe when you arrive at the ski resort? E) The bottle will bulge inward and lotion will squirt out when you open it. F) The bottle will bulge inward and air will rush in when you open it. G) The bottle will bulge outward and lotion will squirt out when you open it. H) The bottle will bulge outward and air will rush in when you open it.

12 22) Why do wild llamas living in the high mountains of Peru contain very specialized hemoglobin? A) High partial pressure of O 2 in the atmosphere coupled with increased solubility of O 2 B) High partial pressure of O 2 in the atmosphere coupled with decreased solubility of O 2 C) Low partial pressure of O 2 in the atmosphere coupled with increased solubility of O 2 D) Low partial pressure of O 2 in the atmosphere coupled with decreased solubility of O 2 23) A beaker of water at room temperature (22 o C) is placed into a small, closed environment where the atmospheric pressure is 0 atm. Which one will occur? A) The water will begin to boil when the vapor pressure increases. B) The water will boil until all the water has vaporized & the beaker is empty. C) The water molecules will not have enough kinetic energy to vaporize. D) The water will boil until the vapor pressure prevents the liquid from boiling further. E) The water will only boil when heat is added to it. 24) Please choose all correctly paired examples. I) Graham s Law: A flatulent diffuses through the air. II) Dalton s Law: Atmospheric pressure is the sum of the partial pressures of individual gases. III) Charles s Law: Bubbles of gas exhaled at the bottom of a pool expand as they rise to the surface. IV) Gay-Lussac s Law: Bubbles of gas expand as you bake yeast bread. V) Henry s Law: A soda fizzes more at higher altitudes. A) I, II, IV B) I, II, V C) I, V D) IV, V E) None of these are correct. 25) Thermal pollution occurs when the temperature of a lake or river increases by 1-2 o C. Why does this slight temperature increase cause fish death? A) The temperature increase causes increased kinetic energy of O 2 which decreases its B) The temperature increase causes increased kinetic energy of O 2 which increases its C) The temperature increase causes decreased kinetic energy of O 2 which decreases its D) The temperature increase causes decreased kinetic energy of O 2 which increases its

13 Problems (60%) Please show all your work for any credit. 1) A g sample of impure Mn 2 (CO 3 ) 5 is decomposed with heat ml CO 2 is collected over water at a temperature of o C. The gas is collected at an atmospheric pressure of 763 torr. Water has a vapor pressure of 79 torr at o C. What is the % Mn 2 (CO 3 ) 3 in the original impure sample? Mn 2 (CO 3 ) 3 Mn 2 O CO 2 2) 2 C 2 H 6 (g) + 2 NH 3 (g) + 3 O 2 (g) 2 C 3 H 3 N (g) + 6 H 2 O (g) What will the partial pressure of C 3 H 3 N be when g O 2 reacts with excess ethane and ammonia in a stoppered ml flask at o C? Please assume the temperature doesn t change during the reaction. 3) What is the molar mass of the dry gas collected in this 100-mL eudiometer (gas collection tube)? Mass of Eudiometer Mass of Eudiometer + Gas Volume of Gas in Eudiometer Temperature of Gas in Flask Barometric Pressure of Gas g g ml 89.0 o C 879 torr 4) What is the total pressure in this flask after the stopcock is opened & the gases are allowed to mix at a constant temperature? 1.82 L N L O atm 0.82 atm 5) A sample of gas has a volume of 1.25 L when the pressure on it is 15.0 atm at a temperature of o C. What temperature will it have when the pressure increases to 16.0 atm and the volume increases to 1.30 L? 6) A gas has an empirical formula of C 3 H 7. The gas has a density of g/l at STP. What is the molecular formula?

14 7) Air bags are activated when a severe impact causes a steel ball to compress a spring and electrically ignite a detonator cap. This causes sodium azide to decompose explosively according to the following reaction: 2 NaN 3 (s) 2 Na (s) + 3 N 2 (g) What volume will the air bag occupy if the bag is packed with g NaN 3 (s) when the air temperature inside the car is 22.0 o C and the atmospheric pressure is 765 mm Hg? 8) A Ziploc bag has a volume of 2877 ml. The atmospheric pressure is 768 mm Hg & the air temperature is 19.5 o C. What mass of CaCO 3 and volume of 1.22 M HCl are necessary in the bag to completely fill it with CO 2? Ignore the HCl volume and negligible H 2 O that occupy space in the Ziploc bag. CaCO 3 (s) + 2 HCl (aq) CaCl 2 (aq) + H 2 O (l) + CO 2 (g) Please use the following information to answer questions In experiment #1, a g sample of an organic compound composed entirely of carbon, hydrogen and oxygen was burned to produce g CO 2 and g H 2 O. Assume complete combustion. 9) What is the empirical formula of this gaseous hydrocarbon? 10) In experiment #2, a different g sample of the gaseous hydrocarbon is analyzed. It occupies L at 238 o C and 808 mm Hg. What is the molecular formula of this gaseous hydrocarbon?

15 AP Chemistry Test (Chapter 5) Name Multiple Choice (50%) 1) 14) 2) 15) 3) 16) 4) 17) 5) 18) 6) 19) 7) 20) 8) 21) 9) 22) 10) 23) 11) 24) 12) 25) 13) Problems (60%) Please show all your work for any credit. 1) Please use only the front side of each piece of paper. 2) Please number your problems clearly and consecutively. 3) Please staple your problems to the back of this page in numerical order. 4) Please write on the paper in the conventional manner. 5) Please do not make a separate list of answers. Record your answer at the end of the work supporting your answer. 6) Please circle/box your answer to any problems.