Physics: Principle and Applications, 7e (Giancoli) Chapter 13 Temperature and Kinetic Theory 13.1 Conceptual Questions 1) Which two temperature changes are equivalent? A) 1 K = 1 F° B) 1 F° = 1 C° C) 1 C° = 1 K D) none of the above Answer: C Var: 1 2) The temperature in your classroom is closest to A) 68 K. B) 68°C. C) 50°C. D) 295 K. Answer: D Var: 1 3) As shown in the figure, a bimetallic strip, consisting of metal G on the top and metal H on the bottom, is rigidly attached to a wall at the left. The coefficient of linear thermal expansion for metal G is greater than that of metal H. If the strip is uniformly heated, it will A) curve upward. B) curve downward. C) remain horizontal, but get longer. D) remain horizontal, but get shorter. E) bend in the middle. Answer: B Var: 1 1 Copyright © 2014 Pearson Education, Inc. 4) Consider a flat steel plate with a hole through its center as shown in the figure. When the temperature of the plate is increased, the hole will A) expand only if it takes up more than half the plate's surface area. B) contract if it takes up less than half the plate's surface area. C) always contract as the plate expands into it. D) always expand with the plate. E) remain the same size as the plate expands around it. Answer: D Var: 1 5) The coefficient of linear expansion for aluminum is 1.8 × 10-6 K-1. What is its coefficient of volume expansion? A) 9.0 × 10-6 K-1 B) 5.8 × 10-18 K-1 C) 5.4 × 10-6 K-1 D) 3.6 × 10-6 K-1 E) 0.60 × 10-6 K-1 Answer: C Var: 1 6) Two metal spheres are made of the same material and have the same diameter, but one is solid and the other is hollow. If their temperature is increased by the same amount, A) the solid sphere becomes bigger than the hollow one. B) the hollow sphere becomes bigger than the solid one. C) the two spheres remain of equal size. D) the solid sphere becomes denser and the hollow one less dense. E) the solid sphere becomes less dense and the hollow one denser. Answer: C Var: 1 2 Copyright © 2014 Pearson Education, Inc. 7) Two containers of equal volume each hold samples of the same ideal gas. Container A has twice as many molecules as container B. If the gas pressure is the same in the two containers, the correct statement regarding the absolute temperatures TA and TB in containers A and B, respectively, is A) TA = TB. B) TA = 2TB. C) TA = TB. D) TA = TB. E) TA = TB. Answer: C Var: 1 8) Consider two equal-volume flasks of gas at the same temperature and pressure. One gas, oxygen, has a molecular mass of 32. The other gas, nitrogen, has a molecular mass of 28. What is the ratio of the number of oxygen molecules to the number of nitrogen molecules in these flasks? A) B) C) D) E) Answer: E Var: 1 9) An ideal gas is held in a container of volume V at pressure p. The rms speed of a gas molecule under these conditions is v. If now the volume and pressure are changed to 2V and 2p, the rms speed of a molecule will be A) v/2 B) v C) 2v D) 4v E) v/4 Answer: C Var: 1 3 Copyright © 2014 Pearson Education, Inc. 10) A mole of diatomic oxygen molecules and a mole of diatomic nitrogen molecules are at STP. Which statements are true about these molecules? (There could be more than one correct choice.) A) Both gases have the same average molecular speeds. B) Both gases have the same number of molecules. C) Both gases have the same average kinetic energy per molecule. D) Both gases have the same average momentum per molecule. Answer: B, C Var: 1 11) The root-mean-square speed of the molecules of an ideal gas is v. The gas is now slowly compressed to one-half its original volume with no change in temperature. What is the rootmean-square speed of the molecules now? A) 4v B) 2v C) v/ D) v E) v/2 Answer: D Var: 1 12) A sample of an ideal gas is heated and its Kelvin temperature doubles. If the root-meansquare speed of its molecules was originally v, what is the new root-mean-square speed? A) 4v B) 2v C) v D) v/ E) v/4 Answer: C Var: 1 13) The absolute temperature of an ideal gas is directly proportional to which of the following quantities? A) the average speed of its molecules B) the average momentum of its molecules C) the average kinetic energy of its molecules D) the mass of its molecules E) It is proportional to all of the above quantities. Answer: C Var: 1 4 Copyright © 2014 Pearson Education, Inc. 14) The absolute temperature of a gas is T. In order to double the rms speed of its molecules, what should be the new absolute temperature? A) 4T B) 2T C) T D) 8T E) 16T Answer: A Var: 1 15) Oxygen molecules are 16 times more massive than hydrogen molecules. At a given temperature, the average molecular kinetic energy of oxygen molecules, compared to that of hydrogen molecules, A) is greater. B) is less. C) is the same. D) cannot be determined without knowing the pressure and volume. Answer: C Var: 1 16) Oxygen molecules are 16 times more massive than hydrogen molecules. At a given temperature, how do their average molecular speeds compare? The oxygen molecules are moving A) four times faster than the hydrogen molecules. B) at 1/4 the speed of the hydrogen molecules. C) sixteen times faster than the hydrogen molecules. D) at 1/16 the speed of the hydrogen molecules. E) at 1/ the speed of the hydrogen molecules. Answer: B Var: 1 17) A fixed container holds oxygen and helium gases at the same temperature. Which of the following statements are correct? (There could be more than one correct choice.) A) The oxygen molecules have the greater average kinetic energy. B) The helium molecules have the greater average kinetic energy. C) The oxygen molecules have the greater speed. D) The helium molecules have the greater speed. E) The helium molecules have the same average kinetic as the oxygen molecules. Answer: D, E Var: 1 5 Copyright © 2014 Pearson Education, Inc. 13.2 Problems 1) Express a body temperature 98.6°F in Celsius degrees. A) 37.0°C B) 45.5°C C) 66.6°C D) 72.6°C Answer: A Var: 1 2) Express -40°C in °F. A) -72°F B) -54°F C) -40°F D) 4.4°F Answer: C Var: 1 3) The temperature changes from 35°F during the night to 75°F during the day. What is the temperature change on the Celsius scale? A) 72 C° B) 40 C° C) 32 C° D) 22 C° Answer: D Var: 1 4) A temperature change of 20 C° corresponds to a Fahrenheit temperature change of A) 68 F°. B) 11 F°. C) 36 F°. D) 18 F°. Answer: C Var: 1 5) At what, if any, temperature are the numerical readings on the Fahrenheit and Celsius scales the same? A) -30° B) -40° C) -50° D) -60° E) They can never read the same because they are based on different zeroes. Answer: B Var: 1 6 Copyright © 2014 Pearson Education, Inc. 6) Oxygen condenses into a liquid at approximately 90 K. What temperature, in degrees Fahrenheit, does this correspond to? A) -193°F B) -217°F C) -265°F D) -297°F Answer: D Var: 2 7) What is absolute zero on the (a) Celsius scale and (b) on the Fahrenheit scale? Answer: (a) -273°C (b) -460°F Var: 1 8) Nitrogen boils at -196°C. What is the corresponding temperature in the Fahrenheit scale? A) -315°F B) -196°F C) -346°F D) -290°F E) -321°F Answer: E Var: 1 9) The weather outside is frightful. The temperature is -22°F. What is the corresponding temperature in the Celsius scale? A) -35°C B) -30°C C) -22°C D) -20°C E) -12°C Answer: B Var: 1 10) Platinum melts at 3215°F. What is the corresponding temperature in the Kelvin scale? A) 2041 K B) 2135 K C) 2207 K D) 2296 K E) 3215 K Answer: A Var: 1 7 Copyright © 2014 Pearson Education, Inc. 11) The coefficient of linear expansion of steel is 12 × 10-6 K-1. What is the change in length of a 25-m steel bridge span when it undergoes a temperature change of 40 K from winter to summer? A) 1.2 cm B) 1.4 cm C) 1.6 cm D) 1.8 cm E) 2.0 cm Answer: A Var: 1 12) A steel bridge is 1000 m long at -20°C in winter. What is the change in length when the temperature rises to 40°C in summer? The average coefficient of linear expansion of this steel is 11 × 10-6 K-1. A) 0.33 m B) 0.44 m C) 0.55 m D) 0.66 m Answer: D Var: 1 13) An aluminum rod 17.400 cm long at 20°C is heated to 100°C. What is its new length? Aluminum has a linear expansion coefficient of 25 × 10-6 K-1. A) 17.435 cm B) 17.365 cm C) 0.348 cm D) 0.0348 cm Answer: A Var: 1 14) By what length will a slab of concrete that is originally 18 m long contract when the temperature drops from 24°C to -16°C? The coefficient of linear thermal expansion for this concrete is 1.0 × 10-5 K-1. A) 0.50 cm B) 0.72 cm C) 1.2 cm D) 1.5 cm Answer: B Var: 1 8 Copyright © 2014 Pearson Education, Inc. 15) A hole in a brass plate has a diameter of 1.200 cm at 20°C. What is the diameter of the hole when the plate is heated to 220°C? The coefficient of linear thermal expansion for brass is 19 × 10-6 K-1. A) 1.205 cm B) 1.195 cm C) 1.200 cm D) 1.210 cm Answer: A Var: 1 16) A quantity of mercury occupies 400.0 cm3 at 0°C. What volume will it occupy when heated to 50°C? Mercury has a volume expansion coefficient of 180 × 10-6 K-1. A) 450 cm3 B) 409.7 cm3 C) 403.6 cm3 D) 401.8 cm3 Answer: C Var: 1 17) A large vat contains 1.000 L of water at 20°C. What volume will this water occupy when it is heated up to 80°C? Water has a volume expansion coefficient of 210 × 10-6 K-1. A) 1.600 L B) 1.013 L C) 0.987 L D) 0.9987 L Answer: B Var: 1 18) The volume coefficient of thermal expansion for gasoline is 950 × 10-6 K-1. By how many cubic centimeters does the volume of 1.00 L of gasoline change when the temperature rises from 30°C to 50°C? A) 6.0 cm3 B) 12 cm3 C) 19 cm3 D) 37 cm3 Answer: C Var: 1 9 Copyright © 2014 Pearson Education, Inc. 19) For the mercury in a thermometer to expand from 4.00 cm3 to 4.10 cm3, what change in temperature is necessary? The mercury has a volume expansion coefficient of 1.80 × 10-4 K-1. A) 400 C° B) 140 C° C) 14 C° D) 8.2 C° Answer: B Var: 1 20) A mercury thermometer has a glass bulb of interior volume 0.100 cm3 at 10°C. The glass capillary tube above the bulb has an inner cross-sectional area of 0.012 mm2. The coefficient of volume expansion of mercury is 1.8 × 10-4 K-1. If the expansion of the glass is negligible, how much will the mercury rise in the capillary tube when the temperature rises from 5°C to 35°C if the bulb was full at 5°C? A) 0.45 mm B) 4.5 mm C) 45 mm D) 45 cm Answer: C Var: 1 21) The coefficient of linear expansion of copper is 17 × 10-6 K-1. A sheet of copper has a round hole with a radius of 3.0 m cut out of it. If the sheet is heated and undergoes a change in temperature of 80 K, what is the change in the radius of the hole? A) It decreases by 4.1 mm. B) It increases by 4.1 mm. C) It decreases by 8.2 mm. D) It increases by 8.2 mm. E) It does not change. Answer: B Var: 1 22) Suppose that a rigid aluminum wire were to be strung out in a loop that just fits snugly around the equator (assuming a perfectly spherical Earth with a radius of 6.37 × 106 m). If the temperature of the wire is increased by 0.50°C, and the increase in length is distributed equally over the entire length, how far off the ground will the wire loop be if it remained centered on the earth? The coefficient of linear expansion of aluminum is 24 × 10-6 K-1. A) 7.6 mm B) 76 mm C) 76 cm D) 76 m E) 760 m Answer: D Var: 1 10 Copyright © 2014 Pearson Education, Inc. 23) The coefficient of linear expansion of copper is 17 × 10-6 K-1. A block of copper 30 cm wide, 45 cm long, and 10 cm thick is heated from 0°C to 100°C What is the change in the volume of the block? A) 2.3 × 10-5 m3 B) 4.6 × 10-5 m3 C) 5.2 × 10-5 m3 D) 6.9 × 10-5 m3 E) 14 × 10-5 m3 Answer: D Var: 1 24) The coefficient of linear expansion of aluminum is 24 × 10-6 K-1 and the coefficient of volume expansion of olive oil is 0.68 × 10-3 K-1. A novice cook, in preparation of some pesto, fills a 1.00-L aluminum pot to the brim and heats the oil and the pot from an initial temperature of 15°C to 190°C. To his consternation some olive oil spills over the top. How much? A) 0.11 L B) 0.12 L C) 0.13 L D) 0.14 L E) 0.15 L Answer: A Var: 1 25) The coefficient of volume expansion of a certain olive oil is 0.68 × 10-3 K-1. A 1.0-L glass beaker is filled to the brim with olive oil at room temperature. The beaker is placed on a range and the temperature of the oil and beaker increases by 25 C°. As a result, 0.0167 L of olive oil spills over the top of the beaker. Which of the following values is closest to the coefficient of linear expansion of the glass from which the beaker is made? A) 1 × 10-6 K-1 B) 4 × 10-6 K-1 C) 1 × 10-5 K-1 D) 2 × 10-5 K-1 E) 3 × 10-5 K-1 Answer: B Var: 1 11 Copyright © 2014 Pearson Education, Inc. 26) The coefficient of linear expansion of aluminum is 24.0 × 10-6 K-1, and the density of aluminum at 0°C is 2.70 × 103 kg/m3. What is the density of aluminum at 300°C? A) 3.93 × 103 kg/m3 B) 2.73 × 103 kg/m3 C) 2.70 × 103 kg/m3 D) 2.67 × 103 kg/m3 E) 2.64 × 103 kg/m3 Answer: E Var: 1 27) The density of water at 0°C is 999.84 kg/m3 and at 4°C it is 999.96 kg/m3. A 1.0-L container, full to the brim with water at 4.0°C is placed in the refrigerator. By the time that the temperature of the water reaches 0.0°C, what volume of water has spilled from the container, assuming that the contraction of the container is negligible? A) 1.1 × 10-7 m3 B) 1.2 × 10-7 m3 C) 1.3 × 10-7 m3 D) 1.4 × 10-7 m3 E) 1.5 × 10-7 m3 Answer: B Var: 1 28) The coefficient of linear expansion of copper is 17 × 10-6 K-1 and that of steel is 12 × 10-6 K-1. At 12°C a steel rod has a diameter of 2.540 cm and a copper pipe has a diameter of 2.536 cm. Which one of the following quantities is closest to the temperature to which the copper pipe must be heated in order for the unheated steel rod to fit snugly in the copper pipe? A) 53°C B) 81°C C) 93°C D) 105°C E) 143°C Answer: D Var: 1 29) The coefficient of linear expansion of copper is 17 × 10-6 K-1 and that of steel is 12 × 10-6 K-1. At 12°C a steel rod has a diameter of 2.540 cm and a copper pipe has a diameter of 2.536 cm. If they are heated together to a higher temperature, which one of the following quantities is closest to the common temperature at which the steel rod will fit snugly in the copper pipe? A) 310°C B) 330°C C) 340°C D) 350°C E) 380°C Answer: B Var: 1 12 Copyright © 2014 Pearson Education, Inc. 30) A steel pipe 36.0 m long, installed when the temperature was is used to transport superheated steam at a temperature of Steel's coefficient of linear expansion is . The pipe is allowed to expand freely when the steam is transported. What is the increase in the length of the pipe when it is used with the superheated steam? A) 60 mm B) 57 mm C) 54 mm D) 64 mm E) 67 mm Answer: A Var: 50+ 31) An aluminum rod is 10.0 cm long and a steel rod is 80.0 cm long when both rods are at a temperature of 15°C. Both rods have the same diameter. The rods are now joined end-to-end to form a rod 90.0 cm long. If the temperature is now raised from 15°C to 90°C, what is the increase in the length of the joined rod? The coefficient of linear expansion of aluminum is 2.4 × 10-5 K-1 and that of steel is 1.2 × 10-5 K-1. A) 0.90 mm B) 0.81 mm C) 0.72 mm D) 0.63 mm E) 0.99 mm Answer: A Var: 1 32) A brass rod is 69.5 cm long and an aluminum rod is 49.3 cm long when both rods are at an initial temperature of 0° C. The rods are placed in line with a gap of 1.2 cm between them, as shown in the figure. The distance between the far ends of the rods is maintained at 120.0 cm throughout. The temperature of both rods is raised equally until they are barely in contact. At what temperature does contact occur? The coefficients of linear expansion of brass and aluminum are 2.0 ×10-5 K-1 (brass) and 2.4 × 10-5 K-1 (aluminum). A) 470°C B) 440°C C) 420°C D) 490°C E) 510°C Answer: A Var: 1 13 Copyright © 2014 Pearson Education, Inc. 33) A glass flask has a volume of 500 mL at a temperature of 20° C. The flask contains 492 mL of mercury at an equilibrium temperature of 20°C. The temperature is raised until the mercury reaches the 500 mL reference mark. At what temperature does this occur? The coefficients of volume expansion of mercury and glass are 18 ×10-5 K-1 (mercury) and 2.0 ×10-5 K-1 (glass). A) 120°C B) 110°C C) 100°C D) 140°C E) 130°C Answer: A Var: 1 34) A solid object has a volume density ρ0 at a temperature of 315 K. The coefficient of volume expansion for the material of which it is made is 7.00 × 10-5 K-1. What will be its density (in terms of ρ0 at a temperature of 425 K, assuming that it does not melt and that its thermal properties do not change with temperature? Answer: 0.992 ρ0 Var: 1 35) Originally 2.00 mol of gas are at STP. If the temperature changes to 47.0°C and the pressure decreases to half of what it was, how many liters do the two moles now occupy? (1 atm = 101 kPa, R = 8.31 J/mol ∙ K) Answer: 105 L Var: 1 36) How many molecules are in (a) 1.0 cm3 of air at STP and (b) 1.0 cm3 of helium at STP? (R = 8.31 J/mol . K, NA = 6.022 × 1023 molecules/mol) Answer: 2.7 × 1019 molecules in both cases Var: 1 37) If a certain sample of an ideal gas has a temperature of 104°C and exerts a pressure of 2.3 × 104 Pa on the walls of its container, how many gas molecules are present in each cubic centimeter of volume? The ideal gas constant is R = 8.31 J/mol × K and Avogadro's number is NA = 6.022 × 1023 molecules/mol. Answer: 4.4 × 1018 molecules Var: 1 38) A jar holds 2.0 L of ideal nitrogen gas, N2, at STP. The atomic mass of nitrogen is 14.0 g/mol, the ideal gas constant is R = 8.31 J/mol ∙ K, Avogadro's number is NA = 6.022 × 1023 molecules/mol, and 1.00 atm = 101 kPa. (a) How many moles of nitrogen are in the jar? (b) How many nitrogen molecules are in the jar? (c) What is the mass of the nitrogen in the jar? Answer: (a) 0.089 mol (b) 5.4 × 1022 molecules (c) 2.5 g Var: 1 14 Copyright © 2014 Pearson Education, Inc. 39) How many moles are there in 2.00 kg of copper? The atomic weight of copper is 63.5 g/mol and its density is 8.90 g/cm3. A) 15.3 B) 31.5 C) 51.3 D) 53.1 Answer: B Var: 1 40) An ideal gas has a pressure of 2.5 atm, a volume of 1.0 L at a temperature of 30°C. How many molecules are there in this gas? (R = 8.31 J/mol ∙ K,1.00 atm = 101 kPa, NA = 6.022 × 1023) A) 6.1 × 1023 B) 6.0 × 1022 C) 2.4 × 1022 D) 2.3 × 1023 Answer: B Var: 1 41) A car starts out when the air temperature is 288 K and the absolute (total) air pressure in the tires is 500 kPa. After driving a while, the temperature of the air in the tires increases to 298 K. What is the pressure in the tires at that point, assuming their volume does not change? A) 129 kPa B) 483 kPa C) 507 kPa D) 517 kPa E) 532 kPa Answer: D Var: 1 42) An ideal gas occupies 6.00 × 102 cm3 at 20°C. At what temperature will it occupy 1.20 × 103 cm3 if the pressure is held constant? A) 10°C B) 40°C C) 100°C D) 313°C Answer: D Var: 1 15 Copyright © 2014 Pearson Education, Inc. 43) A balloon originally has a volume of 1.0 m3 when the gas in it is at 20°C and under a pressure of 1.0 atm. As it rises in the earth's atmosphere, its volume expands. What will be its new volume if its final temperature and pressure are -40°C and 0.10 atm? A) 2.0 m3 B) 4.0 m3 C) 6.0 m3 D) 8.0 m3 Answer: D Var: 1 44) A certain automobile tire has a volume of 0.0185 m3. If the absolute (or total) pressure in the tire is 500 kPa and the temperature is 298 K, how many molecules are there inside the tire? (R = 8.31 J/mol ∙ K, NA = 6.022 x 1023 molecules/mol) A) 2.25 × 1023 molecules B) 2.25 × 1024 molecules C) 3.25 × 1023 molecules D) 3.25 × 1024 molecules E) 3.25 × 1025 molecules Answer: B Var: 1 45) On a cold day, you take in 4.2 L of air into your lungs at a temperature of 0°C. If you hold your breath until the temperature of the air in your lungs reaches 37°C, what is the volume of the air in your lungs at that point, assuming the pressure does not change? A) 4.2 L B) 4.4 L C) 4.6 L D) 4.8 L E) 5.0 L Answer: D Var: 1 46) Your lungs hold 4.2 L of air at a temperature of 27°C and a pressure of 101.3 kPa. How many moles of air do your lungs hold? (R = 8.31 J/mol ∙ K) A) 0.15 moles B) 0.17 moles C) 0.19 moles D) 0.21 moles E) 0.23 moles Answer: B Var: 1 16 Copyright © 2014 Pearson Education, Inc. 47) A 20.0-L pressure vessel holds 2.00 mol of oxygen at 30°C. What is the pressure inside the vessel? (R = 8.31 J/mol ∙ K) A) 101 Pa B) 101 kPa C) 1.01 MPa D) 2.52 MPa E) 252 kPa Answer: E Var: 1 48) A weather balloon containing 2.0 m3 of hydrogen gas rises from a location at which the temperature is 22°C and the pressure is 101 kPa to a location where the temperature is -39°C and the pressure is 20 kPa. If the balloon is free to expand so that the pressure of the gas inside is equal to the ambient pressure, what is the new volume of the balloon? A) 4.0 m3 B) 6.0 m3 C) 8.0 m3 D) 10 m3 E) 12 m3 Answer: C Var: 1 49) A laboratory vacuum pump can reduce the pressure in a chamber to 1.0 × 10-7 Pa. If the volume of the chamber is 0.500 m3 and the temperature is 27°C, how many molecules are left inside the chamber? (NA = 6.022 × 1023 molecules/mol, R = 8.31 J/mol ∙ K) A) 1.2 × 1013 B) 2.4 × 1013 C) 1.2 × 1012 D) 2.4 × 1012 E) 1.2 × 1014 Answer: A Var: 1 50) A refrigerator has an interior volume of 0.500 m3. The temperature inside the refrigerator in 282 K, and the pressure is 101 kPa. If the molecular weight of air is 29 g/mol, what is the mass of air inside the refrigerator? (R = 8.31 J/mol × K) A) 625 g B) 513 g C) 447 g D) 329 g E) 243 g Answer: A Var: 1 17 Copyright © 2014 Pearson Education, Inc. 51) A vertical cylinder, closed at the bottom end, contains 0.0100 mol of ideal gas. It is fitted at the top with a piston that can move freely. The mass of the piston is 14.0 kg and the initial height of the piston above the bottom of the cylinder is 25 cm. What is the temperature of the gas? (R = 8.31 J/mol ∙ K) A) 290 K B) 413 K C) 3620 K D) 405 K E) 500 K Answer: B Var: 5 52) A gas-filled vertical cylinder, closed at the bottom end, is fitted at the top with a piston that can move freely. The mass of the piston is 10.0 kg, and the initial height of the piston above the bottom of the cylinder is 25 cm. A mass of 8.0 kg is placed on the piston. What is the resulting height of the piston, assuming that the temperature of the ideal gas is kept constant? A) 12 cm B) 13 cm C) 14 cm D) 15 cm E) 16 cm Answer: C Var: 1 53) A quantity of an ideal gas is kept in a rigid container of constant volume. If the gas is originally at a temperature of 19°C, at what temperature will the pressure of the gas double from its original value? A) 91°C B) 38°C C) 311°C D) 273°C E) 122°C Answer: C Var: 1 54) A 5.3 L flask of ideal neon gas (which is monatomic) is at a pressure of 6.0 atm and a temperature of The atomic mass of neon is 20.2 g/mol. What is the mass of the neon gas in the flask. (R = 8.31 J/mol ∙ K, 1 atm = 101 kPa, NA = 6.022 × 1023 molecules/mol) A) 2.7 × 10-2 B) 1.6 × 10-2 C) 1.3 × 101 D) 2.7 × 101 E) 2.7 × 103 Answer: A Var: 50+ 18 Copyright © 2014 Pearson Education, Inc. 55) A 4.2-L flask of ideal neon gas (which is monatomic) is at a pressure of 3.3 atm and a temperature of 450 K. The atomic mass of neon is 20.2 g/mol. How many neon atoms are in the flask? (R = 8.31 J/mol ∙ K, 1 atm = 101 kPa, NA = 6.022 × 1023 molecules/mol) A) 2.3 × 1023 B) 2.3 × 1022 C) 6.9 × 1023 D) 2.3 × 1025 E) 6.9 × 1022 Answer: A Var: 1 56) A 3.9-L volume of ideal neon gas (monatomic) is at a pressure of 5.6 aym and a temperature of The atomic mass of neon is The temperature of the gas is now increased to 430 K and the volume is increased to What is the final pressure of the gas? A) 4.8 atm B) 4.3 atm C) 5.3 atm D) 5.8 atm E) 6.3 atm Answer: A Var: 50+ 57) A 0.40- gas tank holds 7.0 moles of ideal diatomic nitrogen gas at a temperature of The atomic mass of nitrogen is . What is the pressure of the gas? (R = 8.31 J/mol ∙ K, 1 atm = 101 kPa) A) 42 atm B) 37 atm C) 32 atm D) 27 atm E) 22 atm Answer: A Var: 50+ 58) A 24.0-L tank contains ideal helium gas at 27°C and a pressure of 22.0 atm. How many moles of gas are in the tank? (R = 8.31 J/mol ∙ K, 1 atm = 101 kPa) A) 238 mol B) 138 mol C) 17.5 mol D) 21.4 mol E) 76.0 mol Answer: D Var: 1 19 Copyright © 2014 Pearson Education, Inc. 59) A sealed cylinder fitted with a movable piston contains ideal gas at 27°C, pressure 0.500 × 105 Pa, and volume 1.25 m3. What will be the final temperature if the gas is compressed to 0.800 m3 and the pressure rises to 0.820 × 105 Pa? A) 42°C B) 68°C C) 130°C D) 250°C E) 150°C Answer: A Var: 1 60) A sealed container holds 0.020 moles of ideal nitrogen (N2) gas, at a pressure of 1.5 atm and a temperature of 290 K. The atomic mass of nitrogen is 14.0 g/mol. How many molecules of nitrogen are in the container? (R = 8.31 J/mol ∙ K, 1 atm = 101 kPa) A) 1.5 × 1021 mol B) 3.0 × 1021 mol C) 6.0 × 1021 mol D) 1.2 × 1022 mol E) 2.4 × 1022 mol Answer: D Var: 1 61) As shown in the figure, an air pocket at the top of a vertical tube, closed at the upper end and open at the lower, occupies a volume of at the surface of a lake where the air pressure is and the temperature is What is the volume of the air in the pocket if the tube is taken to a depth of 56 meters, where the temperature is Assume that none of the air escapes from the tube. The density of the water in the lake is 1000 kg/m3. Answer: 78 Var: 50+ 62) What is the total translational kinetic energy of the gas in a classroom filled with nitrogen at at The dimensions of the classroom are The Boltzmann constant is 1.3806503 × 10-23 J/K, R = 8.31 J/mol ∙ K, and NA = 6.022 × 1023 molecules/mol. Answer: 3.19 × 107 J Var: 50+ 20 Copyright © 2014 Pearson Education, Inc. 63) A flask contains a mixture of argon and neon gases at a stabilized temperature. The rootmean-square speed of the argon gas is determined to be 1.21 km/s. What is the root-mean-square speed of the neon gas? The atomic mass of argon is 39.95 g/mol, and that of neon is 20.18 g/mol. Answer: 1700 m/s Var: 1 64) (a) At what Celsius temperature is the average kinetic energy of a helium gas atom equal to 6.21 × 10-21 J? The Boltzmann constant is 1.38 × 10-23 J/K . (b) What would be the temperature for radon gas? Answer: (a) 27°C (b) 27°C Var: 1 65) What is the average translational kinetic energy of an ideal gas at constant is 1.38 × 10-23 J/K. A) 1.70 x 10-20 J B) 5.65 x 10-21 J C) 1.13 x 10-17 J D) 3.77 x 10-19 J Answer: A Var: 50+ The Boltzmann 66) A sealed container holds 0.020 moles of ideal nitrogen (N2) gas, at a pressure of 1.5 atm and a temperature of 290 K. The atomic mass of nitrogen is 14.0 g/mol. What is the average translational kinetic energy of a nitrogen molecule? The Boltzmann constant is 1.38 × 10-23 J/K. A) 4.0 ×1021 J B) 6.0 ×1021 J C) 8.0 ×1021 J D) 10 ×1021 J E) 12 ×1021 J Answer: B Var: 1 67) The rms speed of a certain sample of carbon dioxide molecules, with a molecular weight of 44.0 g/mole, is 396 m/s. What is the rms speed of water vapor molecules, with a molecular weight of 18.0 g/mol, at the same temperature as the carbon dioxide? A) 253 m/s B) 387 m/s C) 421 m/s D) 506 m/s E) 619 m/s Answer: E Var: 1 21 Copyright © 2014 Pearson Education, Inc. 68) What is the average translational kinetic energy of a nitrogen molecule in the air in a room in which the air temperature is 17°C? The Boltzmann constant is 1.38 × 10-23 J/K. A) 6.01 × 10-21 J B) 4.00 × 10-21 J C) 5.00 × 10-21 J D) 7.00 × 10-21 J E) 9.00 × 10-21 J Answer: A Var: 1 69) The molecular weight of nitrogen, N2, is 28 g/mol. What is the rms speed of nitrogen molecules in a cooler at 8.0°C? The Boltzmann constant is 1.38 × 10-23 J/K and NA = 6.022 × 1023 molecules/mol. A) 450 m/s B) 500 m/s C) 550 m/s D) 600 m/s E) 650 m/s Answer: B Var: 1 70) At what temperature is the rms speed of hydrogen molecules, H2, which have a molecular weight of 2.02 g/mole, equal to 2.0 km/s? The Boltzmann constant is 1.38 × 10-23 J/K and NA = 6.022 × 1023 molecules/mol. A) 17°C B) 34°C C) 51°C D) 68°C E) 72°C Answer: C Var: 1 71) A 0.50 gas tank holds 3.0 moles of ideal diatomic nitrogen gas at a temperature of The atomic mass of nitrogen is . What is the rms speed of the molecules? (The Boltzmann constant is 1.38 × 10-23 J/K, NA = 6.022 × 1023 molecules/mol.) A) 560 B) 790 C) 390 D) 21 E) 97 Answer: A Var: 50+ 22 Copyright © 2014 Pearson Education, Inc. 72) At what temperature would the root mean square speed of oxygen molecules, O2, be if oxygen behaves like an ideal gas? The mass of one O2 molecule is 5.312 × 10-26 kg, and the Boltzmann constant is 1.38 × 10-23 J/K. A) 0.251 K B) 2090 K C) 6270 K D) 1.52 × 1023 K Answer: A Var: 6 73) If the temperature of a gas is increased from 20°C to 100°C, by what factor does the rms speed of an ideal molecule change? A) 1.1 B) 1.3 C) 2.2 D) 1.6 Answer: A Var: 47 74) An oxygen molecule, O2, falls in a vacuum. From what height must it fall so that its translational kinetic energy at the bottom of its fall equals the average translational kinetic energy of an oxygen molecule at 920 K? The mass of one O2 molecule is 5.312 × 10-26 kg, and the Boltzmann constant is 1.38 × 10-23 J/K. Neglect air resistance and assume that g remains constant at 9.8 m/s2 throughout the fall of the molecule. A) 49 km B) 12 km C) 24 km D) 37 km E) 5.2 km Answer: D Var: 1 75) Dust particles in a grain elevator frequently have masses of the order of 1.0 × 10-9 kg. If, to a first approximation, we model the dust particles as an ideal gas, what would be the rms speed of such a particle in air at 27°C? The Boltzmann constant is 1.38 × 10-23 J/K . A) 3.5 × 10-6 m/s B) 5.6 × 10-5 m/s C) 7.8 × 10-4 m/s D) 5.2 × 10-3 m/s E) 4.9 × 10-2 m/s Answer: A Var: 1 23 Copyright © 2014 Pearson Education, Inc. 76) At what temperature would the root-mean-square speed of hydrogen, H2, molecules equal 11.2 km/s (the earth's escape speed)? The mass of a hydrogen atom is 1.67 × 10-27 kg, and the Boltzmann constant is 1.38 × 10-23 J/K. A) 1.01 × 102 K B) 1.01 × 104 K C) 1.01 × 106 K D) 1.01 × 108 K Answer: B Var: 1 77) If the temperature of an ideal gas is increased from 20°C to 40°C, by what percent does the speed of the molecules increase? A) 3% B) 30% C) 70% D) 100% Answer: A Var: 1 78) If an ideal gas molecule has a speed of 0.50 km/s at 20°C, what is its speed at 80°C? A) 500 m/s B) 550 m/s C) 1000 m/s D) 2000 m/s Answer: B Var: 1 24 Copyright © 2014 Pearson Education, Inc.
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