Suppose you try to cool the kitchen of your house by leaving the refrigerator door open. What happens? Why? Would the result be the same if you left open a picnic cooler full of ice? Explain the reason for any differences.
> When ice melts at 00C, its volume decreases. Is the internal energy change greater than, less than, or equal to the heat added? How can you tell?
> If you are told the initial and final states of a system and the associated change in internal energy, can you determine whether the internal energy change was due to work or to heat transfer? Explain.
> A pot is half-filled with water, and a lid is placed on it, forming a tight seal so that no water vapor can escape. The pot is heated on a stove, forming water vapor inside the pot. The heat is then turned off and the water vapor condenses back to liquid
> It is not correct to say that a body contains a certain amount of heat, yet a body can transfer heat to another body. How can a body give away something it does not have in the first place?
> For the following processes, is the work done by the system (defined as the expanding or contracting gas) on the environment positive or negative? (a). expansion of the burned gasoline–air mixture in the cylinder of an automobile engine; (b). opening a
> You bake chocolate chip cookies and put them, still warm, in a container with a loose (not airtight) lid. What kind of process does the air inside the container undergo as the cookies gradually cool to room temperature (isothermal, isochoric, adiabatic,
> The graph in Fig. P19.36 shows a pV-diagram for 3.25 mol of ideal helium (He) gas. Part ca of this process is isothermal. Fig. P19.36: (a). Find the pressure of the He at point a. (b). Find the temperature of the He at points a, b, and c. (c) How m
> Figure P19.35 shows the pV-diagram for a process in which the temperature of the ideal gas remains constant at 85°C. Figure P19.35: (a). How many moles of gas are involved? (b). What volume does this gas occupy at a? (c). How much work wa
> One-half mole of an ideal gas is taken from state a to state c as shown in Fig. P19.34. Fig. P19.34: (a). Calculate the final temperature of the gas. (b). Calculate the work done on (or by) the gas as it moves from state a to state c. (c). Does hea
> A quantity of air is taken from state a to state b along a path that is a straight line in the pV diagram (Fig. P19.33). Fig. P19.33: (a). In this process, does the temperature of the gas increase, decrease, or stay the same? Explain. (b). If Va = 0.
> A cylinder with a frictionless, movable piston like that shown in Fig. 19.5 contains a quantity of helium gas. Initially the gas is at 1.00 × 105 Pa and 300 K and occupies a volume of 1.50 L. The gas then undergoes two processes. In the firs
> Nitrogen gas in an expandable container is cooled from 50.0 0C to 10.0 0C with the pressure held constant at 3.00 × 105 Pa. The total heat liberated by the gas is 2.50 × 104 J. Assume that the gas may be treated as ideal. Find (a) the number of moles of
> Starting with 2.50 mol of N2 gas (assumed to be ideal) in a cylinder at 1.00 atm and 20.0 0C, a chemist first heats the gas at constant volume, adding 1.36 × 104 J of heat, then continues heating and allows the gas to expand at constant pressure to twice
> (a). One-third of a mole of He gas is taken along the path abc shown in Fig. P19.44. Assume that the gas may be treated as ideal. How much heat is transferred into or out of the gas? (b). If the gas instead went directly from state a to state c along th
> Figure P19.43 shows a pV-diagram for 0.0040 mol of ideal H2 gas. The temperature of the gas does not change during segment bc. Figure P19.43: (a). What volume does this gas occupy at point c? (b). Find the temperature of the gas at points a, b, and c
> Three moles of an ideal gas are taken around cycle acb shown in Fig. P19.42. For this gas, Cp = 29.1 J/mol ∙ K. Process ac is at constant pressure, process ba is at constant volume, and process cb is adiabatic. The temperatures of the g
> You hold an inflated balloon over a hot-air vent in your house and watch it slowly expand. You then remove it and let it cool back to room temperature. During the expansion, which was larger: the heat added to the balloon or the work done by the air insi
> Two moles of an ideal monatomic gas go through the cycle abc. For the complete cycle, 800 J of heat flows out of the gas. Process ab is at constant pressure, and process bc is at constant volume. States a and b have temperatures Ta = 200 K and Tb = 300 K
> Three moles of argon gas (assumed to be an ideal gas) originally at 1.50 × 104 Pa and a volume of 0.0280 m3 are first heated and expanded at constant pressure to a volume of 0.0435 m3, then heated at constant volume until the pressure reaches 3.50 × 104
> A volume of air (assumed to be an ideal gas) is first cooled without changing its volume and then expanded without changing its pressure, as shown by path abc in Fig. P19.39. Fig. P19.39: (a). How does the final temperature of the gas compare with it
> In a hospital, pure oxygen may be delivered at 50 psi (gauge pressure) and then mixed with N2O. What volume of oxygen at 20°C and 50 psi (gauge pressure) should be mixed with 1.7 kg of N2O to get a 50%/50% mixture by volume at 20°C? (a). 0.21 m3; (b). 0
> You have a cylinder that contains 500 L of the gas mixture pressurized to 2000 psi (gauge pressure). A regulator sets the gas flow to deliver 8.2 L/min at atmospheric pressure. Assume that this flow is slow enough that the expansion is isothermal and the
> In another test, the valve of a 500-L cylinder full of the gas mixture at 2000 psi (gauge pressure) is opened wide so that the gas rushes out of the cylinder very rapidly. Why might some N2O condense during this process? (a). This is an isochoric proces
> A thermodynamic system is taken from state a to state c in Fig. P19.38 along either path abc or path adc. Along path abc, the work W done by the system is 450 J. Along path adc, W is 120 J. The internal energies of each of the four states shown in the fi
> The power output of an automobile engine is directly proportional to the mass of air that can be forced into the volume of the engine’s cylinders to react chemically with gasoline. Many cars have a turbocharger, which compresses the air before it enters
> You place a quantity of gas into a metal cylinder that has a movable piston at one end. No gas leaks out of the cylinder as the piston moves. The external force applied to the piston can be varied to change the gas pressure as you move the piston to chan
> You compress a gas in an insulated cylinder— no heat flows into or out of the gas. The gas pressure is fairly low, so treating the gas as ideal is a good approximation. When you measure the pressure as a function of the volume of the ga
> Is it a violation of the second law of thermodynamics to convert mechanical energy completely into heat? To convert heat completely into work? Explain your answers.
> You have recorded measurements of the heat flow Q into 0.300 mol of a gas that starts at T1 = 20.00C and ends at a temperature T2. You measured Q for three processes: one isobaric, one isochoric, and one adiabatic. In each case, T2 was the same. Figure P
> In a cylinder, 1.20 mol of an ideal monatomic gas, initially at 3.60 × 105 Pa and 300 K, expands until its volume triples. Compute the work done by the gas if the expansion is (a). isothermal; (b). adiabatic; (c). isobaric. (d). Show each process in
> Use the conditions and processes of Problem 19.56 to compute. Problem 19.56: A cylinder with a piston contains 0.150 mol of nitrogen at 1.80 × 105 Pa and 300 K. The nitrogen may be treated as an ideal gas. The gas is first compressed isobarically to ha
> A cylinder with a piston contains 0.150 mol of nitrogen at 1.80 × 105 Pa and 300 K. The nitrogen may be treated as an ideal gas. The gas is first compressed isobarically to half its original volume. It then expands adiabatically back to its original volu
> Use the conditions and processes of Problem 19.54 to compute. Problem 19.54: A cylinder with a piston contains 0.250 mol of oxygen at 2.40 × 105 Pa and 355 K. The oxygen may be treated as an ideal gas. The gas first expands isobarically to twice its or
> A cylinder with a piston contains 0.250 mol of oxygen at 2.40 × 105 Pa and 355 K. The oxygen may be treated as an ideal gas. The gas first expands isobarically to twice its original volume. It is then compressed isothermally back to its original volume,
> A monatomic ideal gas expands slowly to twice its original volume, doing 450 J of work in the process. Find the heat added to the gas and the change in internal energy of the gas if the process is (a). isothermal; (b). adiabatic; (c). isobaric.
> A certain ideal gas has molar heat capacity at constant volume CV. A sample of this gas initially occupies a volume V0 at pressure p0 and absolute temperature T0. The gas expands isobarically to a volume 2V0 and then expands further adiabatically to a fi
> An air pump has a cylinder 0.250 m long with a movable piston. The pump is used to compress air from the atmosphere (at absolute pressure 1.01 × 105 Pa) into a very large tank at 3.80 × 105 Pa gauge pressure. (For air, CV = 20.8 J/mol ∙ K.) (a). The pist
> When a system is taken from state a to state b in Fig. P19.37 along path acb, 90.0 J of heat flows into the system and 60.0 J of work is done by the system. Fig. P19.37: (a). How much heat flows into the system along path adb if the work done by the
> Discuss the application of the first law of thermodynamics to a mountaineer who eats food, gets warm and perspires a lot during a climb, and does a lot of mechanical work in raising herself to the summit. The mountaineer also gets warm during the descent
> During certain seasons strong winds called chinooks blow from the west across the eastern slopes of the Rockies and downhill into Denver and nearby areas. Although the mountains are cool, the wind in Denver is very hot; within a few minutes after the chi
> A cube of copper 2.00 cm on a side is suspended by a string. (The physical properties of copper are given in Tables 14.1, 17.2, and 17.3.) The cube is heated with a burner from 20.00C to 90.00C. The air surrounding the cube is at atmospheric pressure (1.
> The engine of a Ferrari F355 F1 sports car takes in air at 20.0°C and 1.00 atm and compresses it adiabatically to 0.0900 times the original volume. The air may be treated as an ideal gas with g = 1.40. (a) Draw a pV-diagram for this process. (b) Find t
> A cylinder contains 0.100 mol of an ideal monatomic gas. Initially the gas is at 1.00 × 105 Pa and occupies a volume of 2.50 × 10-3 m3. (a). Find the initial temperature of the gas in kelvins. (b). If the gas is allowed to expand to twice the initial vo
> During an adiabatic expansion the temperature of 0.450 mol of argon (Ar) drops from 66.0°C to 10.0°C. The argon may be treated as an ideal gas. (a). Draw a pV-diagram for this process. (b). How much work does the gas do? (c). What is the change in int
> A cylinder contains 0.0100 mol of helium at T = 27.0°C. (a). How much heat is needed to raise the temperature to 67.0°C while keeping the volume constant? Draw a pV-diagram for this process. (b). If instead the pressure of the helium is kept constant, h
> A cylinder contains 0.250 mol of carbon dioxide (CO2) gas at a temperature of 27.0°C. The cylinder is provided with a frictionless piston, which maintains a constant pressure of 1.00 atm on the gas. The gas is heated until its temperature increases to 12
> The temperature of 0.150 mol of an ideal gas is held constant at 77.0°C while its volume is reduced to 25.0% of its initial volume. The initial pressure of the gas is 1.25 atm. (a). Determine the work done by the gas. (b). What is the change in its inte
> Propane gas (C3H8) behaves like an ideal gas with γ = 1.127. Determine the molar heat capacity at constant volume and the molar heat capacity at constant pressure.
> An experimenter adds 970 J of heat to 1.75 mol of an ideal gas to heat it from 10.0°C to 25.0°C at constant pressure. The gas does +223 J of work during the expansion. (a). Calculate the change in internal energy of the gas. (b). Calculate g for the ga
> Three moles of an ideal monatomic gas expands at a constant pressure of 2.50 atm; the volume of the gas changes from 3.20 × 10-2 m3 to 4.50 × 10-2 m3. Calculate (a). the initial and final temperatures of the gas; (b). the amount of work the gas does in
> In an experiment to simulate conditions inside an automobile engine, 0.185 mol of air at 780 K and 3.00 × 106 Pa is contained in a cylinder of volume 40.0 cm3. Then 645 J of heat is transferred to the cylinder. (a) If the volume of the cylin
> A gas in a cylinder expands from a volume of 0.110 m3 to 0.320 m3. Heat flows into the gas just rapidly enough to keep the pressure constant at 1.65 × 105 Pa during the expansion. The total heat added is 1.15 × 105 J. (a). Find the work done by the gas.
> Figure E19.8 shows a pV-diagram for an ideal gas in which its absolute temperature at b is one-fourth of its absolute temperature at a. Figure E19.8: (a). What volume does this gas occupy at point b? (b). How many joules of work was done by or on the
> An ideal gas is taken from a to b on the pV-diagram shown in Fig. E19.15. During this process, 700 J of heat is added and the pressure doubles. Fig. E19.15: (a). How much work is done by or on the gas? Explain. (b). How does the temperature of the g
> When water is boiled at a pressure of 2.00 atm, the heat of vaporization is 2.20 × 106 J/kg and the boiling point is 120°C. At this pressure, 1.00 kg of water has a volume of 1.00 × 10-3 m3, and 1.00 kg of steam has a volume of 0.824 m3. (a). Compute th
> The pV-diagram in Fig. E19.13 shows a process abc involving 0.450 mol of an ideal gas. Figure E19.13: (a). What was the temperature of this gas at points a, b, and c? (b). How much work was done by or on the gas in this process? (c) How much heat h
> A gas in a cylinder is held at a constant pressure of 1.80 × 105 Pa and is cooled and compressed from 1.70 m3 to 1.20 m3. The internal energy of the gas decreases by 1.40 × 105 J. (a). Find the work done by the gas. (b). Find the absolute value of the h
> The process abc shown in the pV-diagram in Fig. E19.11 involves 0.0175 mol of an ideal gas. Fig. E19.11: (a). What was the lowest temperature the gas reached in this process? Where did it occur? (b). How much work was done by or on the gas from a to
> Five moles of an ideal monatomic gas with an initial temperature of 127°C expand and, in the process, absorb 1500 J of heat and do 2100 J of work. What is the final temperature of the gas?
> In which situation must you do more work: inflating a balloon at sea level or inflating the same balloon to the same volume at the summit of Mt. McKinley? Explain in terms of pressure and volume change.
> Six moles of an ideal gas are in a cylinder fitted at one end with a movable piston. The initial temperature of the gas is 27.0°C and the pressure is constant. As part of a machine design project, calculate the final temperature of the gas after it has d
> (a). In Fig. 19.7a, consider the closed loop 1→ 3→ 2→ 4→ 1. This is a cyclic process in which the initial and final states are the same. Find the total work done by the system in thi
> A gas undergoes two processes. In the first, the volume remains constant at 0.200 m3 and the pressure increases from 2.00 × 105 Pa to 5.00 × 105 Pa. The second process is a compression to a volume of 0.120 m3 at a constant pressure of 5.00 × 105 Pa. (a)
> During the time 0.305 mol of an ideal gas undergoes an isothermal compression at 22.0 °C, 392 J of work is done on it by the surroundings. (a). If the final pressure is 1.76 atm, what was the initial pressure? (b). Sketch a pV-diagram for the process.
> The graph in Fig. E19.4 shows a pV-diagram of the air in a human lung when a person is inhaling and then exhaling a deep breath. Such graphs, obtained in clinical practice, are normally somewhat curved, but we have modeled one as a set of straight lines
> A thermodynamic system undergoes a cyclic process as shown in Fig. Q19.24. The cycle consists of two closed loops: I and II. (a). Over one complete cycle, does the system do positive or negative work? (b). In each loop, is the net work done by the syst
> A system is taken from state a to state b along the three paths shown in Fig. Q19.23. (a). Along which path is the work done by the system the greatest? The least? (b). If Ub > Ua, along which path is the absolute value of the heat transfer, |Q| , t
> The gas used in separating the two uranium isotopes 235U and 238U has the formula UF6. If you added heat at equal rates to a mole of UF6 gas and a mole of H2 gas, which one’s temperature would you expect to rise faster? Explain.
> If you run a movie film backward, it is as if the direction of time were reversed. In the time-reversed movie, would you see processes that violate conservation of energy? Conservation of linear momentum? Would you see processes that violate the second l
> Suppose that you put a hot object in thermal contact with a cold object and observe (much to your surprise) that heat flows from the cold object to the hot object, making the cold one colder and the hot one hotter. Does this process necessarily violate t
> Give two examples of reversible processes and two examples of irreversible processes in purely mechanical systems, such as blocks sliding on planes, springs, pulleys, and strings. Explain what makes each process reversible or irreversible.
> Are the earth and sun in thermal equilibrium? Are there entropy changes associated with the transmission of energy from the sun to the earth? Does radiation differ from other modes of heat transfer with respect to entropy changes? Explain your reasoning.
> The free expansion of an ideal gas is an adiabatic process and so no heat is transferred. No work is done, so the internal energy does not change. Thus, Q/T = 0, yet the randomness of the system and thus its entropy have increased after the expansion. Wh
> How can the thermal conduction of heat from a hot object to a cold object increase entropy when the same amount of heat that flows out of the hot object flows into the cold one?
> On a sunny day, large “bubbles” of air form on the sun warmed earth, gradually expand, and finally break free to rise through the atmosphere. Soaring birds and glider pilots are fond of using these “thermals” to gain altitude easily. This expansion is es
> In Example 20.4, a Carnot refrigerator requires a work input of only 230 J to extract 346 J of heat from the cold reservoir. Doesn’t this discrepancy imply a violation of the law of conservation of energy? Explain why or why not.
> Two moles of an ideal gas are compressed in a cylinder at a constant temperature of 65.0°C until the original pressure has tripled. (a). Sketch a pV-diagram for this process. (b). Calculate the amount of work done.
> A liquid is irregularly stirred in a well-insulated container and thereby undergoes a rise in temperature. Regard the liquid as the system. Has heat been transferred? How can you tell? Has work been done? How can you tell? Why is it important that the st
> Why must a room air conditioner be placed in a window rather than just set on the floor and plugged in? Why can a refrigerator be set on the floor and plugged in?
> In a test of the effects of low temperatures on the gas mixture, a cylinder filled at 20.0°C to 2000 psi (gauge pressure) is cooled slowly and the pressure is monitored. What is the expected pressure at -5.00°C if the gas remains a homogeneous mixture?
> A large research balloon containing 2.00 × 103 m3 of helium gas at 1.00 atm and a temperature of 15.00C rises rapidly from ground level to an altitude at which the atmospheric pressure is only 0.900 atm (Fig. P19.50). Assume the helium behav
> A monatomic ideal gas that is initially at 1.50 × 105 Pa and has a volume of 0.0800 m3 is compressed adiabatically to a volume of 0.0400 m3. (a). What is the final pressure? (b). How much work is done by the gas? (c). What is the ratio of the final te
> Five moles of monatomic ideal gas have initial pressure 2.50 × 103 Pa and initial volume 2.10 m3. While undergoing an adiabatic expansion, the gas does 1480 J of work. What is the final pressure of the gas after the expansion?
> When you blow on the back of your hand with your mouth wide open, your breath feels warm. But if you partially close your mouth to form an “o” and then blow on your hand, your breath feels cool. Why?
> On a warm summer day, a large mass of air (atmospheric pressure 1.01 × 105 Pa) is heated by the ground to 26.0°C and then begins to rise through the cooler surrounding air. (This can be treated approximately as an adiabatic process; why?) Calculate the t
> A player bounces a basketball on the floor, compressing it to 80.0% of its original volume. The air (assume it is essentially N2 gas) inside the ball is originally at 20.0°C and 2.00 atm. The ball’s inside diameter is 23.9 cm. (a). What temperature does
> Heat Q flows into a monatomic ideal gas, and the volume increases while the pressure is kept constant. What fraction of the heat energy is used to do the expansion work of the gas?
> When a quantity of monatomic ideal gas expands at a constant pressure of 4.00 × 104 Pa, the volume of the gas increases from 2.00 × 10-3 m3 to 8.00 × 10-3 m3. What is the change in the internal energy of the gas?
> During an isothermal compression of an ideal gas, 410 J of heat must be removed from the gas to maintain constant temperature. How much work is done by the gas during the process?
> When a wet cloth is hung up in a hot wind in the desert, it is cooled by evaporation to a temperature that may be 20 C0 or so below that of the air. Discuss this process in light of the second law of thermodynamics.
> Explain why each of the following processes is an example of increasing randomness: mixing hot and cold water; free expansion of a gas; irreversible heat flow; developing heat by mechanical friction. Are entropy increases involved in all of these? Why or
> Does a refrigerator full of food consume more power if the room temperature is 200C than if it is 150C? Or is the power consumption the same? Explain your reasoning.
> A growing plant creates a highly complex and organized structure out of simple materials such as air, water, and trace minerals. Does this violate the second law of thermodynamics? Why or why not? What is the plant’s ultimate source of energy? Explain.
> Some critics of biological evolution claim that it violates the second law of thermodynamics, since evolution involves simple life forms developing into more complex and more highly ordered organisms. Explain why this is not a valid argument against evol
> Compare the pV-diagram for the Otto cycle in Fig. 20.6 with the diagram for the Carnot heat engine in Fig. 20.13. Explain some of the important differences between the two cycles. Fig. 20.6: Fig. 20.13: Otto cycle 2 Heating at constant volume (fu
> Two moles of an ideal gas are heated at constant pressure from T = 27°C to T = 107°C. (a). Draw a pV-diagram for this process. (b). Calculate the work done by the gas.
> Katherine Irving, controller of Lotan Corp., is aware of a pronouncement on accounting changes. After reading the pronouncement, she is confused about what action should be taken on the following items related to Lotan Corp. for the year 2017. 1. In 2017
> The following are three independent, unrelated sets of facts relating to accounting changes. Situation 1: Sanford Company is in the process of having its first audit. The company has used the cash basis of accounting for revenue recognition. Sanford pr
> The following statement is an excerpt from the FASB pronouncement related to interim reporting. Interim financial information is essential to provide investors and others with timely information as to the progress of the enterprise. The usefulness of suc
> Snider Corporation, a publicly traded company, is preparing the interim financial data which it will issue to its stockholders and the Securities and Exchange Commission (SEC) at the end of the first quarter of the 2017–2018 fiscal year. Snider’s financi
