Electrochemistry — A/L Chemistry

What must I remember about Electrochemistry?

• Galvanic cells convert chemical energy into electrical energy spontaneously (ΔG < 0, E°cell > 0); electrolytic cells drive non-spontaneous reactions via external EMF.
• Standard hydrogen electrode (SHE) is the international reference: Pt(s) | H₂(g, 100 kPa) | H⁺(aq, 1 mol dm⁻³), assigned E° = 0.00 V at 298 K.
• Standard electrode potential (E°) measures reduction tendency relative to SHE; more positive E° indicates a stronger oxidizing agent, more negative indicates a stronger reducing agent.
• Standard cell potential: E°cell = E°cathode (reduction) - E°anode (oxidation).
• Faraday's laws of electrolysis: charge Q = I × t; moles of electrons n_e = Q / F (Faraday constant F = 96,485 C mol⁻¹).

Test yourself (1 minute)

1. Thermodynamic spontaneity relation

   ΔG° = -nFE°cell. A positive E°cell indicates a spontaneous cell reaction under standard conditions.

2. Cell shorthand notation

   Anode (oxidation) | electrolyte || electrolyte | Cathode (reduction); double vertical line represents the salt bridge.

3. Salt bridge role

   maintains electrical neutrality by ion migration (e.g. KNO₃ or KCl) without allowing bulk solution mixing.

Practise Electrochemistry questions today

Source: NIE G.C.E. (A/L) Chemistry Syllabus (Unit 13)

Where does Electrochemistry fit in the syllabus?

Grade 13 · Term 2