Question

2. Given the following pairs of half-reactions, please construct a complete balanced oxidation-reduction reaction for each pair of two half-reactions: (Show all work and steps)

a)H₂ →2H⁺ + 2e^-

   Fe²⁺ → Fe³⁺ + e^-

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b) 1/4O₂ (g) + H⁺ + e^- == ½ H₂O

H₂ → 2H⁺ + 2e^-

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c) 2IO₃^- + 12H⁺ + 10e^- == I₂ + 6H₂O

2I^- = I₂ + 2e^-

Answer 1

a) we add two half reactions sushc that total e- gets cancelled out

2H+ (aq) + 2e- -> H2

2Fe2+ (aq) --> Fe3+(aq) + 2e-

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2Fe2+ (aq) + 2H+ (aq) --> 2 Fe3+(aq) + H2 (g)

b) adding in same way as above we get

1/2 O2 + 2H+ (aq) + H2 (g) --> H2O + H2

c) balanced reaction is given by adding IO3- half reaction with 5 times of 2I- --> I2 + 2e-   half reaction

2IO3- + 12H+(aq) + 10 I-(aq) --> 6I2 + 6H2O