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Galvanic Cells and Electrode Potentials: Flashcards

Revise galvanic cells, anode and cathode, cell notation, standard potentials, E°cell, ΔG° = −nFE° and electrolysis.

10 cardsIntermediate

10 cards

  1. Question
    What is a galvanic cell?
    Answer

    A cell that uses a spontaneous redox reaction to produce electricity.

  2. Question
    What happens at the anode and the cathode?
    Answer

    Anode: oxidation. Cathode: reduction. ("An ox, red cat")

  3. Question
    Which way do electrons flow in the external wire?
    Answer

    From the anode to the cathode.

  4. Question
    What does the salt bridge do?
    Answer

    Lets ions move between the half-cells to keep each solution electrically neutral.

  5. Question
    Formula for E°cell?
    Answer

    E°cell=E°cathode−E°anodeE°_\text{cell} = E°_\text{cathode} - E°_\text{anode} (both as reduction potentials)

  6. Question
    E°cell for the Daniell cell (Cu²⁺/Cu +0.34 V, Zn²⁺/Zn −0.76 V)?
    Answer

    +0.34 V − (−0.76 V) = +1.10 V

  7. Question
    Write the cell notation for the Daniell cell.
    Answer

    Zn(s) | Zn²⁺(aq) || Cu²⁺(aq) | Cu(s)

  8. Question
    How are ΔG° and E°cell related?
    Answer

    ΔG°=−nFE°cell\Delta G° = -nFE°_\text{cell}, with F = 96 485 C/mol; positive E° means negative ΔG° (spontaneous).

  9. Question
    Should E° be multiplied by the coefficients in the equation?
    Answer

    No. Potentials do not depend on the amount of substance.

  10. Question
    In electrolysis, how do you find the moles of electrons?
    Answer

    Q=ItQ = It (charge in C), then n(e−)=Q/Fn(e^-) = Q/F.