Problem: O2(g) + 4H+(aq) + 2Zn(s) → 2H2O(l) + 2Zn2+(aq)Part Indicate the half-reaction occurring at Anode.Express your answer as a chemical equation. Identify all of the phases in your answer.Part DIndicate the half-reaction occurring at Cathode.Express your answer as a chemical equation. Identify all of the phases in your answer.

FREE Expert Solution

Recall the mnemonics LEO GER.

Lose               Gain

Electron         Electrons

Oxidation       Reduction


 Oxidation half-reactionlost electrons (electrons are on the product side)   anode
 Reduction half-reactiongained electrons (electrons are on the reactant side) → cathode


Oxidation states:

  • neutral compounds or elements = 0
  • ions = charge of ion


Half reactions:

  • O2(g) + 4H+(aq) → 2H2O(l) 
    • O.S. of H = +1 (no change)
      • In H+ = +1
      • In H2O = +1 (Group 1A, not metal hydride)
    • O.S. of O:
      • In O2 = 0 
      • In H2O: sum of O.S. = 0 (neutral cpd)
      • 2[O.S. of H] + x = 0
      • 2(+1) + x = 0 → x = -2 
      • O.S. of O:  -4 2 (coefficient) = -4
      • Change in oxidation state: 0 → -4 
      • gained 4 e- → reduction  cathode 
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Problem Details

O2(g) + 4H+(aq) + 2Zn(s) → 2H2O(l) + 2Zn2+(aq)

Part 

Indicate the half-reaction occurring at Anode.

Express your answer as a chemical equation. Identify all of the phases in your answer.

Part D

Indicate the half-reaction occurring at Cathode.

Express your answer as a chemical equation. Identify all of the phases in your answer.

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