MSU CEM 484 Spring 2010 Second Hour Exam: Thermodynamics and Equations of State - Prof. Jo, Exams of Chemistry

Download MSU CEM 484 Spring 2010 Second Hour Exam: Thermodynamics and Equations of State - Prof. Jo and more Exams Chemistry in PDF only on Docsity! Michigan State University Spring 2010 CEM 484 Second Hour Exam 5 March This exam consists of four problems on the next six pages. Please examine the booklet to make sure you have a complete examination. Equations are provided on the last two pages. Chemical data are provided in the problems along with constants that you may need. Answer each question in the space provided, continuing on the reverse side of the same page if more space is needed. If a question is not clear, insufficient information is given, or there is an apparent error, please notify a member of the instructional staff immediately. Pay attention to units and to significant figures of your numerical answers. Show your reasoning for all problems on the exam! 1. (30 points) _____________ Name: ________________________ 2. (30 points) _____________ Student #: _____________________ 3. (20 points) _____________ Recitation Section: ______________ 4. (20 points) _____________ ____________________________ Total (100 pts) _____________ Sections: 1 - Th 10:20 2 - W 9:10 3 - F 11:30 4 - F 9:10 Practice Exam 2 - Spring 2011 1 1. 30 points a) Three moles of an ideal gas are expanded reversibly from an initial temperature and volume of 400 K and 1.0L, respectively. The final temperature and volume of the system are 320 K and 5.0 L. Calculate the work for this process if the expansion is done along a path where the temperature is changed according to the following equation, T(K) = -20.0 • V + 420. (CV = 3nR/2, R = 8.31 J/(K•mol) = 0.083 L•bar/(K•mol)) Practice Exam 2 - Spring 2011 2 w = 2b) Calculate the inversion temperature for methane from the data given in part a. Practice Exam 2 - Spring 2011 5 Tinv = 3. 20 points One mole of CH3Cl (g) is compressed reversibly at a constant temperature of 450 K, from an initial pressure of 0.5 bar to a final pressure of 16.0 bar. At this temperature, CH3Cl can be described by the virial equation of state given below Z = PV nRT = 1+ B2P iP, where B2P = 0.06 bar-1 at this temperature. Calculate ∆S for this compression. (CP = 38.7 J/(K•mol), R = 8.31 J/(K•mol) = 0.083 L•bar/(K•mol)) Practice Exam 2 - Spring 2011 6 ∆S = 4. 20 points N indistinguishable particles of mass, m, are constrained to move in a circular path of radius r = 3.0 m. The energy of these particles is given by En = n22 2I , where I = mr2 and n = 0,1,2,…, ∞. Determine the partition function for the system of N particles subjected to the motion described above. Assume that the degeneracy of the energy levels, gn = 1, and that the moment of inertia, I, is so large for the macroscopic ring that the energy levels are essentially continuous. (There are math formulas on the last page of the equation sheet that should be useful.) Practice Exam 2 - Spring 2011 7 Q =