Q: It has been determined that the body can generate 5500 kJ of
It has been determined that the body can generate 5500 kJ of energy during one hour of strenuous exercise. Perspiration is the body’s mechanism for eliminating this heat. How many grams and how many l...
See AnswerQ: The molar heat of vaporization of carbon disulfide, CS2, is
The molar heat of vaporization of carbon disulfide, CS2, is 28.4 kJ/mol at its normal boiling point of 46 °C. How much energy (heat) is required to vaporize 1.0 g of CS2 at 46 °C? How much heat is evo...
See AnswerQ: The molar heat of fusion of benzene is 9.92 kJ
The molar heat of fusion of benzene is 9.92 kJ/mol. Its molar heat of vaporization is 30.7 kJ/mol. Calculate the heat required to melt 8.25 g of benzene at its normal melting point. Calculate the heat...
See AnswerQ: The molar heats of fusion and vaporization for water are 6.
The molar heats of fusion and vaporization for water are 6.02 kJ/mol and 40.6 kJ/mol, respectively, and the specific heat capacity of liquid water is 4.18 J/g °C. What quantity of heat energy is requi...
See AnswerQ: The molar heat of fusion of aluminum metal is 10.79
The molar heat of fusion of aluminum metal is 10.79 kJ/mol, whereas its heat of vaporization is 293.4 kJ/mol. a. Why is the heat of fusion of aluminum so much smaller than the heat of vaporization?...
See AnswerQ: The molar heats of fusion and vaporization for silver are 11.
The molar heats of fusion and vaporization for silver are 11.3 kJ/mol and 250. kJ/mol, respectively. Silver’s normal melting point is 962 °C, and its normal boiling point is 2212 °C. What quantity of...
See AnswerQ: The enthalpy (∆H) of vaporization of water is about seven
The enthalpy (∆H) of vaporization of water is about seven times larger than water’s enthalpy of fusion (41 kJ/mol vs. 6 kJ/mol). What does this tell us about the relative similarities among the solid,...
See AnswerQ: For Exercises 51–60 choose one of the following terms to
For Exercises 51–60 choose one of the following terms to match the definition or description given. a. alloy b. specific heat c. crystalline solid d. dipole–dipole attraction e. equilibrium vapor...
See AnswerQ: For Exercises 51–60 choose one of the following terms to
For Exercises 51–60 choose one of the following terms to match the definition or description given. a. alloy b. specific heat c. crystalline solid d. dipole–dipole attraction e. equilibrium vapor...
See AnswerQ: For Exercises 51–60 choose one of the following terms to
For Exercises 51–60 choose one of the following terms to match the definition or description given. a. alloy b. specific heat c. crystalline solid d. dipole–dipole attraction e. equilibrium vapor...
See AnswerQ: For Exercises 51–60 choose one of the following terms to
For Exercises 51–60 choose one of the following terms to match the definition or description given. a. alloy b. specific heat c. crystalline solid d. dipole–dipole attraction e. equilibrium vapor...
See AnswerQ: For Exercises 51–60 choose one of the following terms to
For Exercises 51–60 choose one of the following terms to match the definition or description given. a. alloy b. specific heat c. crystalline solid d. dipole–dipole attraction e. equilibrium vapor...
See AnswerQ: For Exercises 51–60 choose one of the following terms to
For Exercises 51–60 choose one of the following terms to match the definition or description given. a. alloy b. specific heat c. crystalline solid d. dipole–dipole attraction e. equilibrium vapor...
See AnswerQ: For Exercises 51–60 choose one of the following terms to
For Exercises 51–60 choose one of the following terms to match the definition or description given. a. alloy b. specific heat c. crystalline solid d. dipole–dipole attraction e. equilibrium vapor...
See AnswerQ: For Exercises 51–60 choose one of the following terms to
For Exercises 51–60 choose one of the following terms to match the definition or description given. a. alloy b. specific heat c. crystalline solid d. dipole–dipole attraction e. equilibrium vapor...
See AnswerQ: For Exercises 51–60 choose one of the following terms to
For Exercises 51–60 choose one of the following terms to match the definition or description given. a. alloy b. specific heat c. crystalline solid d. dipole–dipole attraction e. equilibrium vapor...
See AnswerQ: For Exercises 51–60 choose one of the following terms to
For Exercises 51–60 choose one of the following terms to match the definition or description given. a. alloy b. specific heat c. crystalline solid d. dipole–dipole attraction e. equilibrium vapor...
See AnswerQ: Are changes in state physical or chemical changes? Explain. What
Are changes in state physical or chemical changes? Explain. What type of forces must be overcome to melt or vaporize a substance (are these forces intramolecular or intermolecular)? Define the molar h...
See AnswerQ: Why does the process of vaporization require an input of energy?
Why does the process of vaporization require an input of energy? Why is it so important that water has a large heat of vaporization? What is condensation? Explain how the processes of vaporization and...
See AnswerQ: Consider a poor lost soul walking at 5 km/h on
Consider a poor lost soul walking at 5 km/h on a hot day in the desert, wearing only a bathing suit. This person’s skin temperature tends to rise due to four mechanisms: (i) energy is generated by met...
See AnswerQ: If the air temperature is the same as the temperature of your
If the air temperature is the same as the temperature of your skin (about 30°C), your body cannot get rid of heat by transferring it to the air. In that case, it gets rid of the heat by evaporating wa...
See AnswerQ: A physicist uses a cylindrical metal can 0.250 m high
A physicist uses a cylindrical metal can 0.250 m high and 0.090 m in diameter to store liquid helium at 4.22 K; at that temperature the heat of vaporization of helium is 2.09 × 104 J/kg. Completely su...
See AnswerQ: You have probably seen people jogging in extremely hot weather. There
You have probably seen people jogging in extremely hot weather. There are good reasons not to do this! When jogging strenuously, an average runner of mass 68 kg and surface area 1.85 m2 produces energ...
See AnswerQ: The units of specific heat c are J/kg ∙ K
The units of specific heat c are J/kg ∙ K, but the units of heat of fusion Lf or heat of vaporization Lv are simply J/kg. Why do the units of Lf and Lv not include a factor of (K)-1 to account for a t...
See AnswerQ: Camels require very little water because they are able to tolerate relatively
Camels require very little water because they are able to tolerate relatively large changes in their body temperature. While humans keep their body temperatures constant to within one or two Celsius d...
See AnswerQ: Evaporation of sweat is an important mechanism for temperature control in some
Evaporation of sweat is an important mechanism for temperature control in some warm-blooded animals. (a). What mass of water must evaporate from the skin of a 70.0-kg man to cool his body 1.00C ? Th...
See AnswerQ: When water is boiled at a pressure of 2.00 atm
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...
See AnswerQ: A pulsed dye laser emits light of wavelength 585 nm in 450
A pulsed dye laser emits light of wavelength 585 nm in 450-ms pulses. Because this wavelength is strongly absorbed by the hemoglobin in the blood, the method is especially effective for removing vario...
See AnswerQ: A sealed container holding 0.500 kg of liquid nitrogen at
A sealed container holding 0.500 kg of liquid nitrogen at its boiling point of 77.3 K is placed in a large room at 21.0°C. Energy is transferred from the room to the nitrogen as the liquid nitrogen bo...
See AnswerQ: The evaporation of perspiration is the primary mechanism for cooling the human
The evaporation of perspiration is the primary mechanism for cooling the human body. Estimate the amount of water you will lose when you bake in the sun on the beach for an hour. Use a value of 1000 W...
See AnswerQ: How much thermal energy is required to boil 2.00 kg
How much thermal energy is required to boil 2.00 kg of water at 100.0°C into steam at 125°C? The latent heat of vaporization of water is 2.26 x 106 J/kg and the specific heat of steam is 2010 J/(kg ∙...
See AnswerQ: When you jog, most of the food energy you burn above
When you jog, most of the food energy you burn above your basal metabolic rate (BMR) ends up as internal energy that would raise your body temperature if it were not eliminated. The evaporation of per...
See AnswerQ: A 60.0-kg runner expends 3.00 x
A 60.0-kg runner expends 3.00 x 102 W of power while running a marathon. Assuming 10.0% of the energy is delivered to the muscle tissue and that the excess energy is removed from the body primarily by...
See AnswerQ: The excess internal energy of metabolism is exhausted through a variety of
The excess internal energy of metabolism is exhausted through a variety of channels, such as through radiation and evaporation of perspiration. Consider another pathway for energy loss: moisture in ex...
See AnswerQ: The boiling temperature of nitrogen at atmospheric pressure at sea level (
The boiling temperature of nitrogen at atmospheric pressure at sea level (1 atm) is −196°C. Therefore, nitrogen is commonly used in low-temperature scientific studies sinc...
See AnswerQ: Steam exiting the turbine of a steam power plant at 100°
Steam exiting the turbine of a steam power plant at 100°F is to be condensed in a large condenser by cooling water flowing through copper pipes (k = 223 Btu/hâ‹…ftâ...
See AnswerQ: Repeat Prob. 17–73E, assuming that a 0.
Repeat Prob. 17–73E, assuming that a 0.01-in-thick layer of mineral deposit (k = 0.5 Btu/h⋅ft⋅°F) has formed on the inner surface of th...
See AnswerQ: Reconsider Prob. 17–73E. Using appropriate software, investigate
Reconsider Prob. 17–73E. Using appropriate software, investigate the effects of the thermal conductivity of the pipe material and the outer diameter of the pipe on the length of the...
See AnswerQ: The boiling temperature of nitrogen at atmospheric pressure at sea level (
The boiling temperature of nitrogen at atmospheric pressure at sea level (1 atm pressure) is −196°C. Therefore, nitrogen is commonly used in low-temperature scientific stu...
See AnswerQ: Repeat Prob. 17–84 for liquid oxygen, which has
Repeat Prob. 17–84 for liquid oxygen, which has a boiling temperature of −183°C, a heat of vaporization of 213 kJ/kg, and a density of 1140 kg/m3 at 1 at...
See AnswerQ: A 1.5-m-diameter, 4-m
A 1.5-m-diameter, 4-m-long cylindrical propane tank is initially filled with liquid propane, whose density is 581 kg/m3. The tank is exposed to the ambient air at 25°C in calm weather. The...
See AnswerQ: Liquid nitrogen is stored in a spherical tank of 1 m diameter
Liquid nitrogen is stored in a spherical tank of 1 m diameter where the tank surface is maintained uniformly at 80 K. The spherical tank is enclosed by a 1.6-m-diameter concentric sphere with uniform...
See AnswerQ: If the temperature surrounding the sunbather in Problem 78 is greater than
If the temperature surrounding the sunbather in Problem 78 is greater than the normal body temperature of 37°C and the air is still, so that radiation, conduction, and convection play no part in cooli...
See AnswerQ: Many species cool themselves by sweating, because as the sweat evaporates
Many species cool themselves by sweating, because as the sweat evaporates, heat is transferred to the surroundings. A human exercising strenuously has an evaporative heat loss rate of about 650 W. If...
See AnswerQ: Humans cool off by perspiring; the evaporating sweat removes heat from
Humans cool off by perspiring; the evaporating sweat removes heat from the body. If the skin temperature is 35.0°C and the air temperature is 28.0°C, what is the entropy change of the universe due to...
See AnswerQ: Hydrogen bonding is responsible for many of the unusual properties of water
Hydrogen bonding is responsible for many of the unusual properties of water (see Sec. 16.1). A simplified model represents a hydrogen bond as the electrostatic interaction of four point charges arrang...
See AnswerQ: In a physics lab, a student accidentally drops a 25.
In a physics lab, a student accidentally drops a 25.0 g brass washer into an open dewar of liquid nitrogen at 77.2 K. How much liquid nitrogen boils away as the washer cools from 293 K to 77.2 K? The...
See AnswerQ: Repeat Problem 1.25 but assume that the surface of the
Repeat Problem 1.25 but assume that the surface of the storage vessel has an absorbance (equal to the emittance) of 0.1. Then determine the rate of evaporation of the liquid oxygen in kilograms per se...
See AnswerQ: An 20-cm-diameter horizontal steam pipe carries 1.
An 20-cm-diameter horizontal steam pipe carries 1.66 kg/min of dry, pressurized, saturated steam at 120°C. If the ambient air temperature is 20°C, deter- mine the rate of condensate flow at the en...
See AnswerQ: At a pressure of 490 kPa, the saturation temperature of sulfur
At a pressure of 490 kPa, the saturation temperature of sulfur dioxide ( SO2) is 32oC, the density is 1350 kg/m3, the latent heat of vaporization is 343 kJ/kg, the absolute viscosity is 3.2 * 10-4 kg/...
See AnswerQ: Two concentric spheres 0.2 m and 0.3 m
Two concentric spheres 0.2 m and 0.3 m in diameter are to be used to store liquid air (133 K). The space between the spheres is evacuated. If the surfaces of the spheres have been flashed with aluminu...
See AnswerQ: Liquid nitrogen is stored in a dewar (see the sketch)
Liquid nitrogen is stored in a dewar (see the sketch) made of two concentric spheres with the space between them evacuated. The inner sphere has an outside diameter of 1 m, and the space between the t...
See AnswerQ: Liquid oxygen (LOX) for the space shuttle is stored at
Liquid oxygen (LOX) for the space shuttle is stored at 90 K prior to launch in a spherical container 4 m in diameter. To reduce the loss of oxygen, the sphere is insulated with superinsulation develop...
See AnswerQ: A cylindrical liquid oxygen (LOX) tank has a diameter of
A cylindrical liquid oxygen (LOX) tank has a diameter of 1.22 m, a length of 6.1 m, and hemispherical ends. The boiling point of LOX is 2179.4oC. An insulation is sought that will reduce the boil-off...
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