Electrochemical Reaction Analysis

Extract

[...] Combination of equations : Numerical Application : E°? = 1.50 V 2 - Nitrogenous species Species : HNO?, NO, Oxidation numbers : +III, Couples : HNO?/NO Half-equations : + 4 + 3 ? NO? + 2 H?O HNO? + + ? NO + H?O Balance equation : + HNO? + ? NO? + NO + H?O Nernst Equations : = E°? + 0.06/3 log = E°? + 0.06 log = E°? + 0.03 log Combined Equation : Numerical Application : E?° = 0.95 V 3 - Cu/Cu²? [...]

[...] M2+ + 4H O ( L ) n 2 3 On constate que = + 5E0 = 3E0 + 2E0 2 3E0 + 2E0 E0 = 1 2 3 5 E0 =1,51 V Le dioxyde de Manganèse est solid, [...]

[...] Conclusion : the reaction is almost total and quantitative. Verification : - When in excess, it is the limiting reagent : (Fe³?) = C V n final (Fe³?) = ? n(Cu) reacts = n(Fe³?) / 2 = ½ C V n(Cu²?) formed = ½ C V m(Cu) deposited = ½ × C V × m(Cu) = 79 mg Charge transferred : Q = n e × F = C V F = C = 6,7 mAh The battery works 6 h 42 min. [...]

[...] MnO2(s) + 4H+ + 2e? ?rrG2 = +2FE2 Bilan: 2MnO?(aq) + 3Mn2+(aq) + 8H+ ? 5MnO2(s) + 4H2O À the balance: ?rrG = 2?rrG1 + 3?rrG2 = ?6FE1 + 6FE2 = 6FE2 ? E1 ? ?G0 = ?RTln K0 ?RTln K0 = 6F(E0 ? E0) 2 1 RT ln K0 = (E0 ? E0) 6F 2 1 ? 0.06log K0 = (E0 ? E0) Application digital: 2 1 E0 ? E0 log K = 0,06 log K0 = 46 ? [...]

[...] E°(MnO??/Mn²?) = 1.51 V E°(Fe³?/Fe²?) = 0.77 V Favored reaction : oxidation of Fe²? by MnO??. Half-equations : MnO?? + 8 + 5 ? Mn²? + 4 H?O Fe²? ? Fe³? + Balance: MnO?? + 8 + 5 Fe²? ? Mn²? + 4 H?O + 5 Fe³? Application numérique : log K° = 5 - K° ? 10? Exercise 6 - Determination of the standard redox potential 1 - Couples : - Au³?/Au = 1.50 - Au?/Au = 1.69 - Global reaction : Au³? + 2 ? Au? [...]