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1. What is the oxidation number of any element in its free state (e.g., Na, O₂)?
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2. What is the oxidation number of oxygen in peroxides (e.g., H₂O₂)?
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3. What is the oxidation number of hydrogen in metal hydrides (e.g., NaH)?
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4. In neutral molecules, the algebraic sum of the oxidation numbers of all elements is:
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5. What is the oxidation number of Mn in KMnO₄?
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6. What is the oxidation number of S in the sulfate ion, SO₄²⁻?
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7. In the reaction K₂Cr₂O₇ + HCl -> KCl + CrCl₃ + Cl₂ + H₂O, the oxidation state of Cr changes from:
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8. In the reaction K₂Cr₂O₇ + HCl -> KCl + CrCl₃ + Cl₂ + H₂O, the oxidation state of some Cl atoms changes from:
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9. The first step in balancing redox equations by the oxidation number method is usually:
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10. The ion-electron method for balancing redox equations involves splitting the reaction into:
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11. When balancing redox equations in acidic medium using the ion-electron method, oxygen atoms are balanced by adding:
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12. When balancing redox equations in acidic medium using the ion-electron method, hydrogen atoms are balanced by adding:
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13. When balancing redox equations in basic medium using the ion-electron method, for each excess oxygen on one side, you add ___ to the same side and ___ to the other side.
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14. In the balanced equation 10Cl⁻ + 16H⁺ + 2MnO₄⁻ -> 5Cl₂ + 2Mn²⁺ + 8H₂O, how many electrons are transferred in total?
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15. Metallic conduction involves the movement of:
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16. Electrolytic conduction involves the movement of:
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17. An electrolytic cell uses electrical energy to drive a:
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18. The process occurring in an electrolytic cell is called:
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19. In an electrolytic cell, the negative electrode is called the:
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20. In an electrolytic cell, the positive electrode is called the:
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21. During electrolysis, oxidation always occurs at the:
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22. During electrolysis, reduction always occurs at the:
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23. In the electrolysis of fused lead bromide (PbBr₂), what is formed at the cathode?
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24. In the electrolysis of fused lead bromide (PbBr₂), what is formed at the anode?
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25. In the electrolysis of aqueous sodium nitrate (NaNO₃) using inert electrodes, what gas is evolved at the cathode?
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26. In the electrolysis of aqueous sodium nitrate (NaNO₃) using inert electrodes, what gas is evolved at the anode?
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27. Down's cell is used for the industrial extraction of:
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28. In Down's cell, the electrolyte is:
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29. Nelson's cell is used for the industrial production of:
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30. In the electrolysis of brine (conc. aq. NaCl) in Nelson's cell, what is produced at the cathode?
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31. Anodized aluminum has a protective coating of:
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32. In the electrolytic purification of copper, the impure copper is used as the:
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33. In the electrolytic purification of copper, the pure copper is used as the:
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34. A voltaic or galvanic cell converts:
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35. A galvanic cell typically consists of two:
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36. In the standard Zn-Cu galvanic cell, the anode is:
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37. In the standard Zn-Cu galvanic cell, the cathode is:
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38. In the standard Zn-Cu galvanic cell, oxidation occurs at the:
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39. In the standard Zn-Cu galvanic cell, reduction occurs at the:
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40. The standard cell potential (E°) for the Zn-Cu galvanic cell is approximately:
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41. The purpose of the salt bridge in a galvanic cell is to:
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42. A reversible cell is one where:
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43. Electrode potential arises from the tendency of a metal to:
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44. Standard electrode potential (E°) is measured under which conditions?
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45. The standard electrode potential of the Standard Hydrogen Electrode (SHE) is arbitrarily set to:
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46. The Standard Hydrogen Electrode (SHE) consists of:
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47. When measuring the standard electrode potential of zinc using SHE, zinc acts as the:
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48. The standard electrode potential (reduction potential) of zinc (Zn²⁺ + 2e⁻ -> Zn) is:
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49. When measuring the standard electrode potential of copper using SHE, copper acts as the:
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50. The standard electrode potential (reduction potential) of copper (Cu²⁺ + 2e⁻ -> Cu) is:
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51. The electrochemical series arranges elements based on their:
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52. In the electrochemical series (reduction potentials), elements with large positive E° values are strong:
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53. In the electrochemical series (reduction potentials), elements with large negative E° values are strong:
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54. A spontaneous redox reaction occurs if the calculated E°cell is:
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55. E°cell is calculated as:
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56. Which metal is generally considered the least reactive based on the electrochemical series?
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57. Which metal will NOT displace hydrogen gas (H₂) from dilute acids?
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58. Will iron (Fe) displace copper (Cu) from a CuSO₄ solution? (E° Fe²⁺/Fe = -0.44V, E° Cu²⁺/Cu = +0.34V)
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59. Will zinc (Zn) displace magnesium (Mg) from a MgSO₄ solution? (E° Zn²⁺/Zn = -0.76V, E° Mg²⁺/Mg = -2.37V)
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60. Cells that cannot be recharged are called:
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61. Cells that can be recharged are called:
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62. The lead accumulator (car battery) is an example of a:
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63. In a fully charged lead accumulator, the anode is made of:
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64. In a fully charged lead accumulator, the cathode is made of:
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65. The electrolyte in a lead accumulator is:
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66. During the discharge of a lead accumulator, both electrodes become coated with:
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67. During the discharge of a lead accumulator, the concentration (density) of the sulfuric acid:
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68. During recharging of a lead accumulator, the reaction PbSO₄ + 2e⁻ -> Pb + SO₄²⁻ occurs at the:
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69. The alkaline battery uses ___ as the anode and ___ as the cathode.
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70. The electrolyte in an alkaline battery is:
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71. The silver oxide battery uses ___ as the anode and ___ as the cathode.
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72. The voltage of a typical silver oxide battery is about:
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73. The Nickel-Cadmium (NiCad) battery uses ___ as the anode and ___ as the cathode.
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74. A major advantage of the NiCad battery is that:
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75. Fuel cells convert chemical energy directly into electrical energy using:
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76. In the common H₂-O₂ fuel cell with KOH electrolyte, hydrogen is ___ at the anode.
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77. In the common H₂-O₂ fuel cell with KOH electrolyte, oxygen is ___ at the cathode.
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78. A significant advantage of fuel cells, especially for space applications, is their: