<p> Chemistry 3202 Electrochemistry Test</p><p>Name: ______January 17, 2014</p><p>Instructions: Place the letter of the correct answer in the spaces provided on this sheet.</p><p>1. How does an Fe atom change into an Fe2+ ion? A. Oxidizes and gains 2 electrons 1. _____ B. Oxidizes and loses 2 electrons C. Reduces and gains 2 protons D. Reduces and loses 2 protons</p><p>2. What is the oxidation number of magnesium in MgSO4? A. -2 B. -1 2. _____ C. +1 D. +2</p><p>3. What is the oxidation half reaction for 2K(s) + F2(g)  2KF(s)? 3. _____ A. K+(aq) + e-  K (s) B. K(s)  K+(aq) + e- C. - - F2(g) + 2e  2F (aq) D. - - 2F (aq)  F2(g) + 2e</p><p>4. Which equation represents a redox equation? 4. _____ A. + 2- Ag2CrO4  2 Ag + CrO4 B. AgNO3 + NaCl  AgCl + NaNO3 C. 2 H2 + O2  2 H2O D. + - H3O + OH  2 H2O</p><p>5. What is the function of a salt bridge in a galvanic cell? A. provides a path for electrons 5. _____ B. a way of automatically replenishing the cell electrolyte C. a means of connecting two half cells while preventing mixing of the two solutions D. a method used to increase the resistance to current flow in the circuit</p><p> o 6. Given the redox reaction below, what is the Ecell for the reaction? 6. _____</p><p>Sn4+(aq) + Co(s)  Co2+(aq) + Sn2+(aq)</p><p>A. -0.43V B. -0.13V C. +0.13V D. +0.43V</p><p>7. If 0.160 mol of a metal produces 46300 coulombs of charge, how many electrons does the metal gain in its half reaction? A. 1 B. 2 7. _____ C. 3 D. 4</p><p>8. Which cell uses electrical energy to cause a non-spontaneous redox reaction? 8. _____ A. Electrochemical B. Electrolytic C. Galvanic D. voltaic</p><p>9. At which electrode does reduction occur in an electrolytic cell? 9. _____ A. anode B. cathode C. salt bridge D. voltmeter 10. Consider an electrochemical cell where the following reaction takes place:</p><p>2 Au3+(aq) + 3 Zn(s) → 2 Au(s) + 3 Zn2+(aq)</p><p>Which of the following is the correct cell notation for this cell? A. Au | Au3+ || Zn2+ | Zn 10. _____ B. Au3+ | Au || Zn | Zn2+ C. Zn | Zn2+|| Au3+ | Au D. Zn | Au3+ || Au | Zn2+</p><p>11. For the electrochemical cell below the E°cell is 0.94V. 11. _____ X(s)|X2+(aq, 1M) || Ag+(aq, 1M) | Ag(s)</p><p>What is the E° value for X2+(aq) + 2e-  X(s)? A. -0.66 V B. -0.14 V C. 0.14 V D. 0.66 V</p><p>12. Which 1.0mol/L salt solution would combine with Mg(s) to give a voltaic cell with the highest voltage? A. Al3+ (aq) 12. _____ B. Cu2+ (aq) C. Fe2+ (aq) D. Zn2+ (aq)</p><p>13. Find the quantity of electricity that results from a current of 3.50A flowing for 6.00min. A. 0.35 C B. 0.58 C 13. _____ C. 21.0 C D. 1.26 x 103 C</p><p>14. What happens to the mass of the chromium electrode in the diagram below? 14. _____</p><p>A. decreases as it oxidizes B. decreases as it is reduced C. increases as it is oxidized D. increases as it is reduced</p><p>15. Which is a primary cell? 15. _____ A. Button B. Hydrogen fuel C. Lead-storage D. Rechargeable Constructed Response: Answer each question in the space provided.</p><p>16. Balance the following redox reactions: A. 2- 3+ H2S + Cr2O7  Cr + S Acidic Solution </p><p>- - - B. MnO4 + CN  MnO2 + OCN Basic Solution </p><p>17. Are the following redox reactions spontaneous as written? Explain. A. Ni(s) + Zn2+(aq)  Ni2+(aq) + Zn(s)</p><p>B. 3Cu2+(aq) + 2Al(s)  3Cu(s) + 2Al3+(aq) 18. Draw a voltaic cell for the following standard cell: Fe (s) | Fe2+ (aq) || Ag+ (aq) | Ag (s) Indicate: 1. Anode 2. Cathode 3. Direction of electron flow 4. Salt Bridge 5. Direction of ion flow 6. Substance Oxidized 7. Substance Reduced 8. Oxidizing Agent 9. Reducing Agent</p><p>19. Aluminum can be produced by the electrolysis of molten aluminum chloride, AlCl3. If a 5.00A current is passed through for 1.50h, what mass of aluminum will be produced? </p>