Galvanic (Voltaic) and Electrolytic Cells - AP Chemistry

1. State the relationship between Gibbs free energy and cell potential.

   $\Delta G = -nFE_{cell}$. Links thermodynamic favorability to electrochemical potential.

2. What is the role of a porous disk in a galvanic cell?

   To allow ion exchange while preventing mixing. Similar to salt bridge but uses physical barrier.

3. Find the cell potential given $E_{cathode} = 0.80$ V and $E_{anode} = 0.40$ V.

   $0.40$ V. Using $E_{cell} = E_{cathode} - E_{anode} = 0.80 - 0.40$.

4. What does a positive cell potential indicate?

   The reaction is spontaneous. Reaction proceeds naturally without external energy input.

5. What is the role of the salt bridge in a galvanic cell?

   To maintain electrical neutrality. Allows ion migration to balance charge as reactions proceed.

6. Identify the charge of the anode in a galvanic cell.

   Negative. Loses electrons during oxidation, creating electron excess.

7. Identify the charge of the cathode in a galvanic cell.

   Positive. Gains electrons during reduction, creating electron deficiency.

8. Which metal acts as a reducing agent in a galvanic cell?

   The metal at the anode. Undergoes oxidation, losing electrons to external circuit.

9. What happens to the mass of the cathode in a galvanic cell during operation?

   It increases. Metal ions deposit as reduction occurs.

10. What occurs at the cathode in a galvanic cell?

    Reduction. Electrons are gained, making cathode the electron destination.

11. What occurs at the cathode in a galvanic cell?

    Reduction. Electrons are gained, making cathode the electron destination.

12. What occurs at the anode in a galvanic cell?

    Oxidation. Electrons are lost, making anode the source of electrons.

13. State the direction of electron flow in an electrolytic cell.

    From cathode to anode. External power source forces electrons from cathode to anode.

14. What is a characteristic of a rechargeable battery in terms of cell type?

    Can act as both galvanic and electrolytic cell. Charging and discharging involve opposite spontaneity directions.

15. What is the standard cell potential $(E^\theta)$ for a galvanic cell?

    Positive. Spontaneous reactions have positive cell potentials.

16. State the relationship between Gibbs free energy and cell potential.

    $\Delta G = -nFE_{cell}$. Links thermodynamic favorability to electrochemical potential.

17. What occurs at the cathode in an electrolytic cell?

    Reduction. Reduction still occurs at cathode regardless of cell type.

18. Identify the charge of the anode in an electrolytic cell.

    Positive. Connected to positive terminal of external power source.

19. State the effect of temperature on cell potential.

    Cell potential generally decreases with increasing temperature. Higher temperature typically reduces driving force for reaction.

20. Define Faraday's constant.

    The charge of one mole of electrons, approximately 96485 C/mol. Fundamental constant relating charge to moles of electrons.

21. What is the main difference between galvanic and electrolytic cells?

    Galvanic cells are spontaneous; electrolytic cells are non-spontaneous. Spontaneity determines whether external power is needed.

22. What is the unit of standard cell potential?

    Volts (V). Standard unit for electrical potential difference.

23. What happens to the mass of the anode in a galvanic cell during operation?

    It decreases. Metal atoms leave electrode as oxidation occurs.

24. What is the standard cell potential $(E^\theta)$ for a galvanic cell?

    Positive. Spontaneous reactions have positive cell potentials.

25. What is the role of the salt bridge in a galvanic cell?

    To maintain electrical neutrality. Allows ion migration to balance charge as reactions proceed.

26. What is the standard cell potential $(E^\theta)$ for an electrolytic cell?

    Negative. Non-spontaneous reactions have negative cell potentials.

27. What is the primary function of a galvanic cell?

    To convert chemical energy into electrical energy. Spontaneous redox reactions drive electron flow through external circuit.

28. Identify the standard conditions for measuring cell potential.

    1 M concentration, 1 atm pressure, 25°C temperature. Standard state conditions for reliable potential measurements.

29. What happens to the mass of the anode in a galvanic cell during operation?

    It decreases. Metal atoms leave electrode as oxidation occurs.

30. What is the role of inert electrodes like platinum?

    To conduct electrons without participating in the reaction. Provide surface for electron transfer without reacting.

31. What occurs at the anode in an electrolytic cell?

    Oxidation. Oxidation still occurs at anode regardless of cell type.

32. What occurs at the cathode in an electrolytic cell?

    Reduction. Reduction still occurs at cathode regardless of cell type.

33. What is the primary function of a galvanic cell?

    To convert chemical energy into electrical energy. Spontaneous redox reactions drive electron flow through external circuit.

34. What is the criterion for a reaction to be spontaneous in terms of $\Delta G$?

    $\Delta G < 0$. Negative free energy indicates thermodynamically favorable process.

35. Identify the charge of the cathode in an electrolytic cell.

    Negative. Connected to negative terminal of external power source.

36. Calculate the equilibrium constant $K$ given $E^\theta = 0.0592$ V and $n = 1$.

    $K = 10$. Using $E^\theta = \frac{0.0592}{n} \log K$ with $n=1$.

37. State the Nernst equation.

    $E = E^\theta - \frac{RT}{nF} \ln Q$. Accounts for concentration effects on cell potential.

38. What is the primary function of a galvanic cell?

    To convert chemical energy into electrical energy. Spontaneous redox reactions drive electron flow through external circuit.

39. What is the purpose of an external circuit in a galvanic cell?

    To allow electron flow. Completes circuit for electron movement between electrodes.

40. Which metal acts as a reducing agent in a galvanic cell?

    The metal at the anode. Undergoes oxidation, losing electrons to external circuit.

41. State the effect of temperature on cell potential.

    Cell potential generally decreases with increasing temperature. Higher temperature typically reduces driving force for reaction.

42. State the function of a power source in an electrolytic cell.

    To provide energy for non-spontaneous reactions. Overcomes negative cell potential of non-spontaneous reactions.

43. What happens to the mass of the anode in a galvanic cell during operation?

    It decreases. Metal atoms leave electrode as oxidation occurs.

44. What occurs at the anode in a galvanic cell?

    Oxidation. Electrons are lost, making anode the source of electrons.

45. What is the formula for the cell potential of a galvanic cell?

    $E_{cell} = E_{cathode} - E_{anode}$. Standard reduction potential difference between electrodes.

46. Calculate $\Delta G$ for a cell with $n=2$, $F=96485$ C/mol, and $E_{cell}=1.1$ V.

    $-212.67$ kJ/mol. Using $\Delta G = -nFE = -(2)(96485)(1.1)$.

47. What is the primary function of an electrolytic cell?

    To convert electrical energy into chemical energy. External power source drives non-spontaneous redox reactions.

48. State the effect of temperature on cell potential.

    Cell potential generally decreases with increasing temperature. Higher temperature typically reduces driving force for reaction.

49. What is the role of the salt bridge in a galvanic cell?

    To maintain electrical neutrality. Allows ion migration to balance charge as reactions proceed.

50. What is the standard cell potential $(E^\theta)$ for a galvanic cell?

    Positive. Spontaneous reactions have positive cell potentials.

51. State the direction of electron flow in a galvanic cell.

    From anode to cathode. Electrons flow from negative anode to positive cathode.

52. What occurs at the cathode in a galvanic cell?

    Reduction. Electrons are gained, making cathode the electron destination.

53. Identify the charge of the anode in a galvanic cell.

    Negative. Loses electrons during oxidation, creating electron excess.

54. Identify the charge of the anode in a galvanic cell.

    Negative. Loses electrons during oxidation, creating electron excess.

55. What does a negative cell potential indicate?

    The reaction is non-spontaneous. External energy required to drive the reaction forward.

56. Which metal acts as a reducing agent in a galvanic cell?

    The metal at the anode. Undergoes oxidation, losing electrons to external circuit.

57. What is the significance of the equilibrium constant $K$ in electrochemistry?

    Relates to cell potential by $E^\theta = \frac{RT}{nF} \ln K$. Large $K$ indicates favorable reaction with positive $E^\theta$.

58. What occurs at the cathode in an electrolytic cell?

    Reduction. Reduction still occurs at cathode regardless of cell type.

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