Part A: Essential Formulas (One-Line Each)

$E^\circ_{cell} = E^\circ_{cath} - E^\circ_{an}$ $E = E^\circ - \frac{0.0592}{n}\log Q \quad \text{(25°C)}$ $E^\circ = \frac{0.0592}{n}\log K \quad \text{(at equilibrium, } E=0\text{)}$ $\Delta G^\circ = -nFE^\circ \quad (F = 96500 \text{ C/mol})$ $w = \frac{MIt}{nF} \quad \text{(Faraday's law; t in seconds)}$ $\Lambda_m = \frac{\kappa \times 1000}{M} \quad \text{(S·cm}^2\text{/mol)}$ $\Lambda^\circ_m = \nu_+\lambda^\circ_+ + \nu_-\lambda^\circ_- \quad \text{(Kohlrausch)}$ $\alpha = \frac{\Lambda_m}{\Lambda^\circ_m} \quad \text{(weak electrolyte dissociation)}$

Part B: Key Electrode Potentials

Part C: Critical Comparison

Part D: Battery Quick Facts

• Dry cell (Leclanché): 1.5 V, not rechargeable, Zn/$MnO_{2}$
• Lead storage: 2 V/cell × 6 = 12 V, rechargeable, Pb/$PbO_{2}$
• Mercury cell: 1.35 V, constant voltage, Zn-Hg/HgO
• Fuel cell ($H_{2}$-$O_{2}$): ~70% efficiency, only water by-product, continuous

Part E: Top 5 NEET Traps

1. Time in Faraday's law MUST be in seconds (not minutes)
2. n for $Cu^{2+}$ = 2 (not 1); n for $Ag^{+}$ = 1; n for $Al^{3+}$ = 3
3. Anode is NEGATIVE in galvanic but POSITIVE in electrolytic
4. O = −1 in peroxides; O = +2 in O$F_{2}$ (not −2)
5. Weak electrolytes: use Kohlrausch's law for Λ°m (not graph extrapolation)

Part F: Kohlrausch's Law Quick Application

$\Lambda^\circ_m(\text{CH}_3\text{COOH}) = \Lambda^\circ_m(\text{CH}_3\text{COONa}) + \Lambda^\circ_m(\text{HCl}) - \Lambda^\circ_m(\text{NaCl})$

Part G: Corrosion Mechanism

• Fe oxidizes at anode (anodic spots): Fe → $Fe^{2+}$ + 2$e^{-}$
• $O_{2}$ reduces at cathode (cathodic spots): $O_{2}$ + $2H_{2}O$ + 4$e^{-}$ → 4$OH^{-}$
• Rust forms: $Fe^{2+}$ + 2$OH^{-}$ → Fe(OH)_{2} --[$O_{2}$]-→ $Fe_{2}O_{3}$·x$H_{2}O$
• Prevention: Zn coating (galvanization), Mg blocks (cathodic protection), painting