This mini-lesson covers Reactivity 3.2: oxidation and reduction, oxidation states, oxidising and reducing agents, and voltaic and electrolytic cells.
Work through each screen, answer the questions as you go (some are wordy, some are calculations) and collect ⭐ stars. Press Start when you're ready.
Redox is electron transfer. Remember OIL RIG:
Oxidation states: free elements = 0; simple ions = their charge; O usually −2, H usually +1; the sum equals the overall charge.
An oxidising agent takes electrons (and is itself reduced); a reducing agent gives electrons (and is oxidised). Redox equations split into two half-equations that must balance for electrons.
A more reactive metal displaces a less reactive one from solution — the basis of the reactivity series.
A voltaic cell uses a spontaneous redox reaction to make electricity. Oxidation happens at the anode (negative), reduction at the cathode (positive); a salt bridge completes the circuit.
The cell voltage is E°cell = E°(cathode) − E°(anode).
An electrolytic cell does the opposite: it uses electrical energy to drive a non-spontaneous redox reaction. Positive ions (cations) move to the cathode to be reduced; negative ions (anions) go to the anode to be oxidised. Used for extracting reactive metals and electroplating.
Tap a phrase, then the box it belongs in.
Tap an item on the left, then its match on the right.
Redox: OIL RIG — oxidation is loss, reduction is gain of electrons
Oxidation states: elements 0; O = −2, H = +1; sum = overall charge
Voltaic cell: spontaneous, makes electricity; E°cell = E°cathode − E°anode
Electrolytic cell: electrical energy drives a non-spontaneous reaction
You've covered Electron transfer — redox for IB Diploma Chemistry SL. Press Finish to see your score.
You've worked through Electron transfer — redox for IB Diploma Chemistry SL. 🎉
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Next: test yourself in the Evaluate stage Confidence Quiz, then lock it in with Verify.