Photoredox and Electrochemical Routes to Radical Intermediates · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

One electron, two ways to push it

Science · Chemistry · ages 23-24
Name ______________________   Date ____________

  1. In a redox pair, what are the giver and the acceptor called?

    • Acid and base
    • Solvent and solute
    • Reductant and oxidant

  2. A species loses an electron in a reaction. What happened to it?

    • It was oxidized
    • It was reduced
    • It stayed unchanged

  3. An electrode at a chosen potential can replace a stoichiometric oxidant and cut waste.

    Circle one:   True   False

  4. A catalyst potential sits below the substrate's need and nothing happens. What does that tell you?

    • Single electron transfer is not feasible there
    • The half-reaction method failed
    • Transfer is feasible anyway

  5. The excited catalyst donates an electron first, then accepts one later. Which cycle is it?

    • Reductive quenching
    • Oxidative quenching
    • No quenching at all

  6. Why split a redox change into half-reactions?

    • To hide the electrons
    • To balance atoms and charge in each half, then recombine
    • To avoid balancing charge

  7. In a reductive quenching cycle, the excited catalyst gives an electron before taking one.

    Circle one:   True   False

  8. Raising concentration boosts side products while product stalls. What is the fix and why?

    • Heat the mixture further
    • Push harder with more oxidant
    • Dilute: crowded radicals meet each other, not substrate
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Answer key

For grown-ups. Fold this page away before handing over the rest.

One electron, two ways to push it W1-mt_YhqzHGcx31-s1

  1. Reductant and oxidant · The giver reduces its partner; the acceptor oxidizes its partner.
  2. It was oxidized · Losing electrons is oxidation; gaining them is reduction.
  3. True · The electrode supplies or removes electrons directly instead of being consumed.
  4. Single electron transfer is not feasible there · Potentials decide feasibility before any cycle can run.
  5. Oxidative quenching · Give-first order defines the oxidative cycle.
  6. To balance atoms and charge in each half, then recombine · Separate halves make electron bookkeeping exact.
  7. False · Reductive means take-first; give-first is the oxidative order.
  8. Dilute: crowded radicals meet each other, not substrate · Dilution routes radicals toward substrate encounters.
Worksheet · LightMySky