16.16 Galvanic Cell (Keynotes with lesson planner, mcqs)
⚡ Daniel cell · galvanic
@everexams.com📅 lesson planner
🔋 from redox to electricity
Oxidation‑reduction reactions can be used to produce electricity. When a zinc plate is dipped in CuSO₄ solution, zinc oxidizes and copper plates out, but electrons transfer directly. To harness electricity, we separate the half‑reactions.
Figure 16.8 – Daniel cell: Zn in ZnSO₄ | porous partition | Cu in CuSO₄
At anode (oxidation): Zn(s) → Zn²⁺(aq) + 2e⁻ E°ox = +0.76 V
At cathode (reduction): Cu²⁺(aq) + 2e⁻ → Cu(s) E°red = +0.34 V
Overall: Zn(s) + Cu²⁺(aq) → Zn²⁺(aq) + Cu(s) E°cell = 1.10 V
📌 key notes
✅ 16.8 quick check (solved)
1. Compare an electrolytic and a galvanic cell.
➤ Galvanic cell: spontaneous redox → electricity, anode negative, cathode positive.
➤ Electrolytic cell: electricity forces non‑spontaneous reaction, anode positive, cathode negative.
2. Write reactions for Zn‑Mg galvanic cell.
➤ Mg oxidized (anode): Mg(s) → Mg²⁺ + 2e⁻
➤ Zn²⁺ reduced (cathode): Zn²⁺ + 2e⁻ → Zn(s)
➤ Overall: Mg(s) + Zn²⁺(aq) → Mg²⁺(aq) + Zn(s)
