The complete lecture — electrochemistry comes alive in the live panel as you read. Scroll down; the animation keeps pace, and you can build a cell to measure its EMF.
1 — Oxidation & reduction (redox)
OIL RIG: Oxidation Is Loss, Reduction Is Gain (of electrons).
2 — Oxidation numbers
- Free element 0 · O = −2 · H = +1 · sum = overall charge.
3 — Oxidising & reducing agents
- Oxidising agent — is reduced (KMnO₄, O₂). Reducing agent — is oxidised (metals, H₂).
4 — Balancing redox equations
Zn + Cu²⁺Zn → Zn²⁺ + 2e⁻ · Cu²⁺ + 2e⁻ → Cu
5 — Galvanic (voltaic) cells
Anode = oxidation (−); cathode = reduction (+). Electrons flow anode → cathode.
6 — Salt bridge & cell notation
Cell notationZn(s) | Zn²⁺ ‖ Cu²⁺ | Cu(s)
7 — Standard electrode potential
| Electrode | E° (V) |
|---|
| Zn²⁺/Zn | −0.76 |
| 2H⁺/H₂ | 0.00 |
| Cu²⁺/Cu | +0.34 |
| Ag⁺/Ag | +0.80 |
8 — EMF of a cell
EMFE°cell = E°cathode − E°anode · positive → spontaneous
Choose the two electrodes in the live panel and read off the cell voltage.
9 — Electrolytic cells & electrolysis
Molten NaCl → Na (cathode) + Cl₂ (anode). Electrical energy → chemical change.
10 — Faraday's laws
ChargeQ = I t · 1 F = 96 500 C
11 — Applications
- Batteries · electroplating · refining · corrosion & its prevention.
12 — Exam recap
- Redox (OIL RIG); oxidation numbers.
- Oxidising/reducing agents; half-reactions.
- Galvanic cell, salt bridge, cell notation.
- Electrode potential & the series.
- E°cell = E°cathode − E°anode.
- Electrolysis; Faraday's laws.