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Unformatted text preview: Chemistry 131 Final Exam 18 December 2009 7:15 p.m. to 10:15 p.m. Name: ________________________ ID #: ________________________ This exam consists of ten (10) questions, one extra credit problem, and 2 pages of potentially useful information. Please check BEFORE you begin to make sure that you have a complete exam. Please do all your work on the pages provided. You may use the backside of pages for additional work, but please tell us that you are doing so (i.e. an arrow with a note in clear English saying "more work on back"). SHOW ALL WORK . GIVE UNITS for all answers that require them. Partial credit can only be given for those answers for which work is provided. CIRCLE YOUR ANSWER. We ask this so that we don't have to interpret what you intended as your final answer. If you make any 5% approximations you will not receive credit if the approximation is not valid. Also if you need to use the quadratic formula, you need to SET UP THE CALCULATION and INSERT THE RELEVANT NUMBERS INTO THE FORMULA . Credit will not be given for answers that appear out of nowhere due to a fancy calculator. Assume all gases are ideal. GOOD LUCK and HAPPY HOLIDAYS! Prob. 1(35) 2(35) 3(30) 4(30) 5(30) 6(35) Score Prob. 7(40) 8(35) 9(30) 10(30) E.C.(5) Total (330) Score U N I V E R S I T Y O F University of Rochester Rochester, New York 14627-0216 COLLEGE OF ARTS AND SCIENCE DEPARTMENT OF CHEMISTRY ROCHESTER The following calculations can be done either without a calculator or with minimal work and you do NOT need to show calculations. 1a) (4 pts) Circle the solution or solutions that constitute a buffer . (all equal volumes) 1.0 M HNO 2 and 0.5 M NaNO 2 1.0 M HNO 3 and 0.5 M NaNO 3 0.5 M CH 3 NH 2 and 0.4 M CH 3 NH 3 Cl 0.5 M NaOH and 0.5 M HCl b) (4 pts) Ignoring any weak acid-base equilibrium processes, which of the following has the highest molar solubility (circle the correct answer)? FeS CdS PbSO 4 PbS c) (3 pts) Calculate the pH of a 0.1 M HCl solution. pH = __________ d) (4 pts) You mix 3.646 g of HCl (36.46 g/mol) into 1.00 L of a 0.1 M NaOH solution. pH = _____ e) (4 pts) Which solid produces the highest concentration of total ions when placed into 1.0 L of water? 10 g potassium sulfide 10 g sodium sulfide 20 g cadmium sulfide 30 g lead sulfide f) (4 pts) Consider a solution that is 0.437 M NH 3 and 0.427 M NH 4 Cl. Circle all true statements pH > 7.0 [OH- ] < [H + ] Contains a strong acid Is a buffer Consider the dissolution reaction AgI (s) Ag + (aq) + I- (aq) g) (4 pts) If the solubility of AgI increases as the temperature is raised, this reaction is Exothermic Endothermic Neither Endo or Exothermic Not Enough Information h) (4 pts) If you added some of the strong electrolyte KI to the above AgI solution at equilibrium, the equilibrium would shift Left Right Stay the Same Not Enough Information i) (4 pts) If you had a saturated AgI solution, you would find the ion product Q sp is related to the solubility product K sp as (circle the correct answer)...
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This note was uploaded on 03/23/2011 for the course CHM 131 taught by Professor Krugh during the Fall '04 term at Rochester.
- Fall '04