Thermodynamics

710 | Thermodynamics13–21C How is the P-v-T behavior of a component in anideal-gas mixture expressed? How is the P-v-T behavior of acomponent in a real-gas mixture expressed?13–22C What is the difference between the component pressureand the partial pressure? When are these two equivalent?13–23C What is the difference between the component volumeand the partial volume? When are these two equivalent?13–24C In a gas mixture, which component will have thehigher partial pressure—the one with the higher mole numberor the one with the larger molar mass?13–25C Consider a rigid tank that contains a mixture oftwo ideal gases. A valve is opened and some gas escapes. Asa result, the pressure in the tank drops. Will the partial pressureof each component change? How about the pressurefraction of each component?13–26C Consider a rigid tank that contains a mixture oftwo ideal gases. The gas mixture is heated, and the pressureand temperature in the tank rise. Will the partial pressure ofeach component change? How about the pressure fraction ofeach component?13–27C Is this statement correct? The volume of an idealgasmixture is equal to the sum of the volumes of each individualgas in the mixture. If not, how would you correct it?13–28C Is this statement correct? The temperature of anideal-gas mixture is equal to the sum of the temperatures ofeach individual gas in the mixture. If not, how would youcorrect it?13–29C Is this statement correct? The pressure of an idealgasmixture is equal to the sum of the partial pressures ofeach individual gas in the mixture. If not, how would youcorrect it?13–30C Explain how a real-gas mixture can be treated as apseudopure substance using Kay’s rule.13–31 A rigid tank contains 8 kmol of O 2 and 10 kmol ofCO 2 gases at 290 K and 150 kPa. Estimate the volume of thetank. Answer: 289 m 313–32 Repeat Prob. 13–31 for a temperature of 400 K.13–33 A rigid tank contains 0.5 kmol of Ar and 2 kmol of N 2at 250 kPa and 280 K. The mixture is now heated to 400 K.Determine the volume of the tank and the final pressure of themixture.13–34 A gas mixture at 300 K and 200 kPa consists of 1 kgof CO 2 and 3 kg of CH 4 . Determine the partial pressure ofeach gas and the apparent molar mass of the gas mixture.13–35E A gas mixture at 600 R and 20 psia consists of1 lbm of CO 2 and 3 lbm of CH 4 . Determine the partial pressureof each gas and the apparent molar mass of the gas mixture.13–36 A 0.3-m 3 rigid tank contains 0.6 kg of N 2 and 0.4 kgof O 2 at 300 K. Determine the partial pressure of each gasand the total pressure of the mixture.103.9 kPa, 282.0 kPaAnswers: 178.1 kPa,13–37 A gas mixture at 350 K and 300 kPa has the followingvolumetric analysis: 65 percent N 2 , 20 percent O 2 , and15 percent CO 2 . Determine the mass fraction and partial pressureof each gas.13–38 A rigid tank that contains 1 kg of N 2 at 25°C and300 kPa is connected to another rigid tank that contains 3 kgof O 2 at 25°C and 500 kPa. The valve connecting the twotanks is opened, and the two gases are allowed to mix. If thefinal mixture temperature is 25°C, determine the volume ofeach tank and the final mixture pressure. Answers: 0.295 m 3 ,0.465 m 3 , 422 kPaN 21 kg25°C300 kPaAr1 kmol220 K5 MPaFIGURE P13–38O 23 kg25°C500 kPa13–39 A volume of 0.3 m 3 of O 2 at 200 K and 8 MPa ismixed with 0.5 m 3 of N 2 at the same temperature and pressure,forming a mixture at 200 K and 8 MPa. Determine thevolume of the mixture, using (a) the ideal-gas equation ofstate, (b) Kay’s rule, and (c) the compressibility chart andAmagat’s law. Answers: (a) 0.8 m 3 , (b) 0.79 m 3 , (c) 0.80 m 313–40 A rigid tank contains 1 kmol of Ar gas at 220 Kand 5 MPa. A valve is now opened, and 3 kmolof N 2 gas is allowed to enter the tank at 190 K and 8 MPa.The final mixture temperature is 200 K. Determine the pressureof the mixture, using (a) the ideal-gas equation of stateand (b) the compressibility chart and Dalton’s law.FIGURE P13–40N 23 kmol190 K8 MPa13–41 Reconsider Prob. 13–40. Using EES (or other)software, study the effect of varying the molesof nitrogen supplied to the tank over the range of 1 to 10kmol of N 2 . Plot the final pressure of the mixture as a functionof the amount of nitrogen supplied using the ideal-gasequation of state and the compressibility chart with Dalton’slaw.