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Unformatted text preview: THE UNIVERSITY OF MANITOBA April 25 20 11 Final EXAMINATION PAPER NO: PAGE NO: 1 of 8 DEPARTMENT & COURSE NO: CHEM 1310 TIME: 3 HOURS EXAMINATION: University I Chemistry: Intro. To Phys. Chem. EXAMINER: CHEM 1310 Committee PART B: Part B will be marked out of a raw score of 30 (or 50% of the 60 marks allotted to this final examination). Part B should require approximately 90 min. to complete. DO ALL of QUESTIONS 1 THROUGH 5. NAME: ( Please Print Legibly ) SIGNATURE: STUDENT NUMBER: Examination Room: Seat Number: For Examiners use only: 1: 2: 3: ________________ 4: 5: ________________ Total: /30 INSTRUCTIONS: ALL NUMERICAL ANSWERS MUST BE JUSTIFIED WITH PROPER AND CLEAR CALCULATIONS! DONT FORGET UNITS AND SIG FIGS IN YOUR FINAL ANSWERS OR MARKS WILL BE DEDUCTED. No examination booklets are needed. The questions are to be answered on the pages of this examination as indicated. Blank pages, to the extent that they are not needed for your answers, may also be used for any rough work required to prepare your answer. NOTE THAT YOU MUST ANSWER ALL FIVE QUESTIONS ON THIS PAPER. The allocated marks for each question are shown in brackets to the right of the page after the question. Some information that you may find useful in answering this examination will be found on the DATA PAGES attached to Part A of this examination. Paper: CHEM 1310 University I Chemistry: Intro. to Phys. Chem. Page: 2 of 8 (if more space is required to answer these questions, continue on the back side of this page) QUESTION 1 Recently in Japan, the Fukushima nuclear power plant was severely damaged by the tsunami that followed an earthquake. Fuel rods containing uranium oxide pellets provide the heat which is used to drive steam turbines that generate electricity. One of the damaged reactors was Unit 1 which provides 460 megawatts or 4.60 10 8 J/s of power. a) Radioactive fission of 235 92 U releases 3.20 10 11 J per nucleus. What mass of 235 92 U would be required to provide 460 megawatts of power each day? (4 marks) The total daily energy output = 4.60 10 8 J/s 60 s/min 60 min/hr 24 hr/day = 3.974 10 13 J/day Let E U be the energy released per mole of 235 92 U. Therefore E U = 6.022 10 23 atoms/mol 3.20 10-11 J/atom = 1.927 10 13 J/mol Let n U = the number mols of uranium used each day. Then n U E U = 3.974 10 13 J. Therefore n U 1.927 10 13 = 3.974 10 13 n U = 3.974 10 13 /1.927 10 13 = 2.062 mols Hence the mass of 235 92 U required = 235 g/mol 2.062 mols = 485 g b) What mass of coal (assumed to be solid carbon) must be burned to release the equivalent amount of energy? ( H f (CO 2 ) = 393.5 kJ/mol) (3 marks) C(s) + O 2 (g) CO 2 (g) H = -393.5 kJ Therefore the amount of heat energy released by 1 mole of coal = 3.935 10 5 J....
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- Fall '11