Chemistry Homework question

Question

Consider the following two unbalanced reduction half-reactions and their associated standard reduction potentials:

BrO3−(aq)⟶HBrO(aq)  E∘=1.45VBrOX3X−(aq)⟶HBrO(aq)  EX∘=1.45V

VO2+(aq)⟶VO2+  E∘=1.00VVOX2X+(aq)⟶VOX2+  EX∘=1.00V

Consider the spontaneous reaction powering a galvanic (voltaic, electrochemical) cell under acidic conditions.

(a) What is the balanced oxidation half reaction?

(b) What is the balanced reduction half reaction?

(c) What is the balanced overall reaction, and 𝐸∘𝑐𝑒𝑙𝑙Ecell∘?

(d) Provide the short-hand electrochemical cell notation for this galvanic cell.

Answer 1

a) VO²⁺ + H₂O ==> VO₂⁺ + 2H⁺ + e- oxidation half reaction Eºox = -1.00 V

b) BrO3- + 5H+ + 4e- ==> HBrO + 2H2O reduction half reaction Eºred = +1.45 V

c) 4VO2⁺ + BrO₃^- + 2H₂O ==> 4VO₂⁺ + HBrO + 3H⁺ overall redox reaction Eºcell = 0.45 V