Chemistry 112 Name Final Exam Form A Section December 17,

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Chemistry 112 Name Final Exam Form A Section December 17, 2012 email IMPORTANT: On the scantron (answer sheet), you MUST clearly fill your name, your student number, section number, and test form

1 Chemistry 112 Name Final Exam Form A Section December 17, IMPORTANT: On the scantron (answer sheet), you MUST clearly fill your name, your student number, section number, and test form (white cover = test form A; yellow cover = test form B). Use a #2 pencil. CHEMISTRY 112 FINAL EXAM DECEMBER 17, 2012 FORM A 1. The half-life for a given first order reaction is determined to be 2.5 min. What is the concentration of the reactant remaining after 7.0 minutes if the initial concentration of A is 2.4 M? A. 1.2 M B. 2.5 M C M D M E M 2. Given the following mechanism where reactants A and B form C, which graph below correctly depicts the linear relationship between the concentration of B and time? A + B AB* (slow) AB* + A C (fast) A. B. There are 40 questions on this exam. Check that you have done all of the problems and filled in the first 40 bubbles on the scantron. The maximum score on this exam is 40 points. Your score will be reported in percent (max 100%). Exam policy Hints Calculators with text-programmable memory are not allowed. Relevant data and formulas, including the periodic table, are attached at the end of this exam. Your grade will be based only on what is on the scantron form. The answer key will be posted on the web after the exam (on the Exam Schedule page). You must turn in your cover sheet with your scantron answer form. As you read the question, underline or circle key words to highlight them for yourself. Avoid errors from "mis-reading" the question. Pay attention to units and magnitudes (decimal places) of numbers obtained from calculations. There is no penalty for guessing. C. D. E.

2 3. For a known reaction the temperature dependence of its rate constant was determined. Using the graph below and its given linear equation, what is the activation energy of the reaction? y = 514 x A kj/mol B. 514 kj/mol C kj/mol D kj/mol E kj/mol 1/T (1/Kelvin) 5. The mechanism of the depletion of ozone is described below. What substance is acting as the catalyst? A. O 3 B. ClO C. Cl D. O E. O 2 2Cl (g) + 2 O 3(g) 2ClO (g) + 2 O 2(g) 2ClO (g) + hν 2 Cl (g) + 2O (g) O (g) + O (g) O 2(g) 6. Silicon has an enthalpy of fusion of 50.2 kj/mol and a melting point of 1414 C. What is the entropy of fusion of silicon? 4. The isotope 57 Co is a commonly used gamma source, with a half-life of 272 days. If the source needs to be replaced when its radiation falls below 30% of the original sample, in how many days does the source need to be replaced? A. 15 days A J/mol-K B J/mol-K C J/mol-K D J/mol-K E J/mol-K B. 20 days C. 3 days D. 51 days E. 473 days 7. Which substance produces an acidic aqueous solution? A. NaBr B. KOH C. Na(CO 2CH 3) D. LiF E. NH 4I

3 8. What will be the ph in the titration of 50 ml of 0.10 M acetic acid (CH 3COOH) when 25 ml of 0.10 M NaOH has been added at 25 C? (Note that this is the half-equivalence point; K a for acetic acid is 1.8 x 10 5.) A. 2.6 B. 5.1 C. 7.0 D. 4.7 E What is the volume of 0.4 M HCl that you would need to completely neutralize 248 ml of a 0.27 M solution of Sr(OH) 2? A. 335 ml B. 167 ml C. 248 ml D. 500 ml E. 105 ml 10. What is the ground state electron configuration for an Fe 2+ ion? A. [Ar] 4s 2 3d 6 B. [Ar] 4s 1 3d 5 C. [Ar] 4s 2 3d 4 D. [Ar] 3d 6 E. [Kr] 4s 2 3d Which of the following metals would you use to prevent corrosion of Zn? A. Fe B. Mn C. Pb D. Co E. Ni 12. What current you would you use to plate 1.8 grams of Chromium in 8.0 hours from an aqueous solution of Cr(NO 3) 3? A Amps B Amps C Amps D. 418 Amps E Amps 13. What is the voltage of the cell pictured below at 25 C? A V B V C V D V E V Cd NaNO 3 Cr 0.4M Cd(NO 3 ) 2 2.2M Cr(NO 3 ) 3

4 14. Which of the following can be done to a metal to reduce the motion of dislocations? 17. In the following reaction, what is Ni 2+ acting as? A. Add select impurities to the metal to make an alloy. B. Heat the metal to allow atoms to rearrange. C. Add HCl to the metal. D. Run a current through the metal. E. Oxidize the metal. 15. Which one of the following metal complexes will be attracted to a magnet? A. an oxidizing agent B. a Lewis acid C. a Lewis base D. a chelate E. a ligand Ni 2+ (g) + 6H 2O (l) Ni(H 2O) 6 2+ (aq) A. [Fe(CN) 6] 2+ (strong field ligand) B. [TiCl 4] (weak field ligand) C. [Mn(OH 2) 6] 2+ (weak field ligand) D. [Co(en) 3] 3+ (strong field ligand) E. [Zn(EDTA)] 2 (weak field ligand) 16. What color will a metal complex appear if it is found to absorb photons of E = 200 kj/mol? A. Green B. Blue C. Yellow D. Violet E. Red 18. Of the following substances, which is least likely to behave as a semiconductor? A. GaP B. InSb C. ZnSe D. NaF E. Ge 19. A solid white powder is found to be a non-conductor of electricity, have a melting point of 45 C and is insoluble in water. The substance is most likely a(n): A. Ionic solid B. Covalent network solid C. Pure Metal D. Molecular Solid E. Metal Alloy

5 20. Given the polymer shown below, what is the monomer? 22. What is the conjugate base of H 2O? A. H 3O + B. H 2O 2 C. O 2 D. HOH E. OH 23. Which of the following substances has the STRONGEST conjugate base? A. B. C. A. HF B. HBr C. HClO 4 D. HNO 3 E. HClO 3 D. E. 21. According to molecular orbital theory, what is the bond order of any diatomic molecule containing equal numbers of bonding and anti-bonding electrons? A. 0 B. 1 C. 2 D. 3 E. 1/2 24. Which reaction below corresponds to the K a for NH 4 +? A. NH 3 + H 2O NH OH B. NH H 2O NH OH C. NH H 2O OH + H + + NH 3 D. NH H 2O NH 3 + H 3O + E. NH H 3O + NH 3 + H 2O + H 2

6 25. How many ions will be present in solution when 1 mole of [Cr(NH 3) 4Cl 2]Cl is dissolved in water? A x ions B x ions C x ions D. 2 ions E. 4 ions 27. Which nuclide is likely to be radioactive? A K B Bi C Ni D Xe 26. Uranium-233 undergoes fission according to the nuclear reaction below. Identify the species X. E Nb A Cf B Nb C La D Tc E Nb 28. What is the mass defect when breaking a single aluminum-27 nucleus into separated protons and neutrons if an aluminum-27 nucleus has a mass of amu? A g B x g C x g D x 10 8 g E x g 29. What is the ph of a M aqueous solution of phenol (C 6H 5OH) at 25 C? (K a for phenol is 1.3 x ) A B x 10 6 C D E. 6.34

7 30. Which of the following oxides would form an acidic aqueous solution? 33. What is the standard emf for the following reaction? A. Cs 2O B. CuO C. NO 2 D. SrO E. Na 2O A V B V C V D V E V 3 Fe 2+ (aq) Fe (s) + 2 Fe 3+ (aq) 31. In which of the following processes does the entropy of the system decrease? A. the volume of a gas increases B. a solid sublimes C. equal volumes of ethanol and water are mixed to form a solution D. a solid freezes E. the temperature of the system increases 32. The equilibrium constant for the following reaction is at 25 C. What is the value of ΔG for this reaction? A. +22 kj/mol B. 4.2 kj/mol C. 25 kj/mol D. 50 kj/mol E. 22 kj/mol N 2 (g) + 3H 2 (g) 2NH 3 (g) 34. What name is given to the interactions that make vulcanized rubber much stronger and more rigid than natural poly-isoprene (natural rubber)? A. Sulfide bonds B. Cross-links C. Carbon-sulfides D. Bridge bonds E. Hydrogen bonds 35. What is the final coefficient in front of water when the following reaction is balanced in basic solution? A. 2 B. 3 C. 4 D. 0 E. 12 MnO 4 (aq) + Fe (s) Mn 2+ (aq) + Fe 3+ (aq)

8 36. Using the energy diagram provided, predict which one of the following ions would be expected to be diamagnetic: σ* 2p σ* 2p π* 2p π* 2p σ 2p 37. What is the ph of a solution with initial concentrations of 0.1 M (CH 3) 3N and 0.2 M (CH 3) 3NHCl at 25 C? (K b for (CH 3) 3N = 6.4 x 10 5 ) A B C D E π 2p π 2p σ 2p σ* 2s σ* 2s σ 2s σ 2s σ* 1s σ* 1s σ 1s σ 1s Small 2s 2p Interaction (O 2, F 2, Ne 2 ) Large 2s 2p Interaction (B 2, C 2, N 2 ) A. + O 2 B. 2 N 2 C. + Li 2 D. C 2 E. 2+ Be What is the poh of a 0.08 M solution of NaOBr at 25 C? (K a for HOBr is 2.5 x 10 9.) A B C D E The solubility of manganese (II) hydroxide (Mn(OH) 2) is M. What is the K sp of Mn(OH) 2? A B C D E Go on to the last page

9 40. The K f for [Ag(NH 3) 2] + is 1.7 x If the original concentration of an aqueous Ag + solution is 1.5 M before adding ammonia, and the final concentration of free Ag + ions in solution is M, what is the final concentration of ammonia in the solution? (Neglect the volume change upon addition of ammonia.) A M B M C M D M E M END OF TEST

CHEMISTRY 112 FINAL EXAM APRIL 29, 2013 FORM A

CHEMISTRY 112 FINAL EXAM APRIL 29, 2013 FORM A Chemistry 112 Name Final Exam Form A Section April 29, 2013 email IMPORTANT: On the scantron (answer sheet), you MUST clearly fill your name, your student number, section number, and test form (white cover