ACC2601 Assignment 6 2025

ACC2601
ASSIGNMENT 6 2025

UNIQUE NO.
DUE DATE: 2025

, ACC2601 Assignment 6 2025

1. Redox reactions at 25 °C, 1 bar

Given: i) Sn(s) + Sn⁴⁺(aq) ⇌ Sn²⁺(aq) ii) Sn(s) + AgBr(s) ⇌ SnBr₂(aq) + Ag(s) iii) Cd(s) +
CuSO₄(aq) ⇌ Cu(s) + CdSO₄(aq) iv) Cu²⁺(aq) + Cu(s) ⇌ Cu⁺(aq)

Standard potentials used (25 °C): Sn⁴⁺/Sn²⁺ = +0.151 V; Sn²⁺/Sn = −0.136 V AgBr(s)
+ e⁻ → Ag(s) + Br⁻, E° ≈ +0.071 V Cu²⁺/Cu = +0.340 V; Cu⁺/Cu = +0.521 V; Cu²⁺/Cu⁺ =
+0.153 V Cd²⁺/Cd = −0.403 V
∘
∘ ∘ ∘ 𝑛𝐸 cell
Use: 𝐸cell = 𝐸red(cathode) + 𝐸ox(anode) and log10 𝐾 = 0.05916
(25 °C).




1.1 Reduction and oxidation half-reactions (each case)

(i) Ox: Sn(s) → Sn²⁺(aq) + 2e⁻ (E°ox = +0.136 V) Red: Sn⁴⁺(aq) + 2e⁻ → Sn²⁺(aq)
(E°red = +0.151 V)

(ii) (note 2 electrons overall → two AgBr) Ox: Sn(s) → Sn²⁺(aq) + 2e⁻ (E°ox = +0.136
V) Red: AgBr(s) + e⁻ → Ag(s) + Br⁻(aq) (E°red = +0.071 V)

(iii) Ox: Cd(s) → Cd²⁺(aq) + 2e⁻ (E°ox = +0.403 V) Red: Cu²⁺(aq) + 2e⁻ → Cu(s)
(E°red = +0.340 V)

(iv) Ox: Cu(s) → Cu⁺(aq) + e⁻ (E°ox = −0.521 V) Red: Cu²⁺(aq) + e⁻ → Cu⁺(aq)
(E°red = +0.153 V)




1.2 Overall cell reactions

(i) Sn(s) + Sn⁴⁺(aq) → 2 Sn²⁺(aq)

(ii) Sn(s) + 2 AgBr(s) → SnBr₂(aq) + 2 Ag(s)