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Lecture Thermodynamics: An engineering approach (8/e): Chapter 13 - Yunus A. Çengel, Michael A. Boles

Chapter 13 - Gas mixtures. The objectives of Chapter 13 are to: Develop rules for determining nonreacting gas mixture properties from knowledge of mixture composition and the properties of the individual components; define the quantities used to describe the composition of a mixture, such as mass fraction, mole fraction, and volume fraction; apply the rules for determining mixture properties to idealgas mixtures and real-gas mixtures;. | Chapter 13 Gas Mixtures Study Guide in PowerPoint to accompany Thermodynamics: An Engineering Approach, 8th edition by Yunus A. Çengel and Michael A. Boles The discussions in this chapter are restricted to nonreactive ideal-gas mixtures. Those interested in real-gas mixtures are encouraged to study carefully the material presented in Chapter 12. Many thermodynamic applications involve mixtures of ideal gases. That is, each of the gases in the mixture individually behaves as an ideal gas. In this section, we assume that the gases in the mixture do not react with one another to any significant degree. We restrict ourselves to a study of only ideal-gas mixtures. An ideal gas is one in which the equation of state is given by Air is an example of an ideal gas mixture and has the following approximate composition. Component % by Volume N2 78.10 O2 20.95 Argon 0.92 CO2 + trace elements 0.03 Definitions Consider a container having a volume V that is filled with | Chapter 13 Gas Mixtures Study Guide in PowerPoint to accompany Thermodynamics: An Engineering Approach, 8th edition by Yunus A. Çengel and Michael A. Boles The discussions in this chapter are restricted to nonreactive ideal-gas mixtures. Those interested in real-gas mixtures are encouraged to study carefully the material presented in Chapter 12. Many thermodynamic applications involve mixtures of ideal gases. That is, each of the gases in the mixture individually behaves as an ideal gas. In this section, we assume that the gases in the mixture do not react with one another to any significant degree. We restrict ourselves to a study of only ideal-gas mixtures. An ideal gas is one in which the equation of state is given by Air is an example of an ideal gas mixture and has the following approximate composition. Component % by Volume N2 78.10 O2 20.95 Argon 0.92 CO2 + trace elements 0.03 Definitions Consider a container having a volume V that is filled with a mixture of k different gases at a pressure P and a temperature T. A mixture of two or more gases of fixed chemical composition is called a nonreacting gas mixture. Consider k gases in a rigid container as shown here. The properties of the mixture may be based on the mass of each component, called gravimetric analysis, or on the moles of each component, called molar analysis. k gases T = Tm V = Vm P = Pm m = mm The total mass of the mixture mm and the total moles of mixture Nm are defined as Note that The composition of a gas mixture is described by specifying either the mass fraction mfi or the mole fraction yi of each component i. The mass and mole number for a given component are related through the molar mass (or molecular weight). To find the average molar mass for the mixture Mm , note Solving for the average or apparent molar mass Mm The apparent (or average) gas constant of a mixture is expressed as Can you show that Rm is given as To change from a mole .