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SCX Chemistry · Chapter 2: Oxidation, reduction, oxidants and reductants

Year 11 SCX · About 15 minutes with activities · Turn your sound on

Chapter 2 · Oxidants and reductants
2Na + Br₂ → 2NaBrsodium + bromine → sodium bromide
No oxygen here!so what does “oxidised” mean?
Na loses electronsso sodium is oxidised
OIL RIGabout electrons
Reductantoxidised · electron giver
Oxidantreduced · electron taker
S: +4 → +6SO₂ is oxidised
Fe: +3 → +2Fe³⁺ is reduced
Redox detective5 cases · solve at least 3

Chapter 2 recap

  • Oxidation states: if the ON of an atom increases, it has undergone oxidation; if it decreases, reduction. If one is oxidised, the other has to be reduced.
  • OIL RIG: oxidation is loss of electrons, loss of hydrogen or gain of oxygen. Reduction is gain of electrons, gain of hydrogen or loss of oxygen.
  • Oxidant = the species reduced (causes oxidation of another). Reductant = the species oxidised (causes reduction of another). Justify with electron-transfer and ON-change sentences.
  • Next: Chapter 3 · Half equations and overall redox equations

Sodium is “oxidised” with no oxygen in sight, and it’s called the reductant. Why?

Chapter 2 · About 15 minutes · sound on

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