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Oxidation Numbers and Redox Reactions: Flashcards

Revise oxidation and reduction, oxidation-number rules, oxidizing and reducing agents and balancing redox equations.

10 cardsIntermediate

10 cards

  1. Question
    What does OIL RIG stand for?
    Answer

    Oxidation Is Loss (of electrons), Reduction Is Gain (of electrons).

  2. Question
    What happens to the oxidation number in oxidation and in reduction?
    Answer

    Oxidation: it increases. Reduction: it decreases.

  3. Question
    What is the oxidation number of an uncombined element, e.g. O₂ or Zn?
    Answer

    0

  4. Question
    Oxidation number of S in H₂SO₄?
    Answer

    +6: 2(+1) + x + 4(−2) = 0

  5. Question
    Oxidation number of Mn in MnO₄⁻?
    Answer

    +7: x + 4(−2) = −1

  6. Question
    What is a reducing agent?
    Answer

    The substance that gives electrons to another; it is itself oxidized.

  7. Question
    What is an oxidizing agent?
    Answer

    The substance that takes electrons from another; it is itself reduced.

  8. Question
    Write the half-equation for zinc being oxidized.
    Answer

    Zn→ZnX2++2 eX−\ce{Zn -> Zn^2+ + 2e-}

  9. Question
    In acid, how do you balance O and H in a half-equation?
    Answer

    Add H₂O to balance O, then H⁺ to balance H, then electrons to balance charge.

  10. Question
    What must be checked at the end of balancing a redox equation?
    Answer

    Both atoms and total charge balance, and electrons lost = electrons gained.