CHEM 105 1nd Edition Lecture 11 Outline of Last Lecture • Cont. Oxidation-Reduction Reactions: Electron Transfer • Cosidering Electron Transfer in Redox Reactions • Balancing Redox Reactions Using Half-Reactions Outline of Current Lecture • Cont. Balancing Redox Reactions • Balance acid Current Lecture-Balance the reaction of aluminum metal and the permanganate ion in basic solution. The products are manganese(IV) oxide and aluminum hydroxide.A: In basic solution, H2o and OH- are used to balance H amd O in the half-reaction. Al(s) + MnO4(aq) ------> MnO2(s) + Al(OH)3(s) Oxidized half-reaction Al(s) + 3OH-(aq) ------> Al(OH)3(s) + 3e-reduction half-reactionMnO4-(aq) + 2H2O(l) + 3e- -----> MnO2 (s) + 4OH-(aq) Al(s) + 3OH-(aq) + MnO-4(aq) + 2H2O(l) +3e- -----> Al(OH)3(s) +3e- + MnO2(s) + 4OH-(aq) Al(s) + MnO4-(aq) + 2H2(l) ------> Al(OH)3(s) + MnO2(s) + OH-(aq) Q: CH3OH(aq) + K2Cr2O7(aq) + H2SO4(aq) -----> CH2O2(aq) + Cr2(SO4)3(aq) + H2O(l) + K2SO4(aq) A: CH3OH(aq) + Cr2O7(aq) + H(aq) ------> CH2O2(aq) + Cr(aq) +H2O(l) Oxidized half-reactionCH3OH(aq) + H2O(l) -----> CH2O2(aq) +4H(aq) + 4e-Reduction half-reactionCr2O2-(aq) + 12H(aq) + 6e- -----> 2Cr3(aq) + 7 H2O(l) 3(CH3OH + H2O) -----> CH2O2 + 4H + 4e- 3CH3OH(aq) + 2Cr2O7(aq) + 16 H+(aq) -----> 3CH2O2(aq) + 4Cr(aq) +
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