tutorial 2 – redox reaction

TUTORIAL 2 – REDOX REACTION

1. A galvanic cell is constructed using the two hypothetical half-reactionsA + e– B E° = 1.50 VC + 2e– D E° = –0.50 V

a. Write down the balanced equation representing the cell reaction.b. Calculate the standard potential of this cell, E°cell.

2. A voltaic cell prepared using aluminum and nickel has the following cell notation.

Al(s) | Al3+(aq) || Ni2+(aq) | Ni(s)

Write:a) Half- cell reaction at anode and cathodeb) Balance overall cell reaction

3. The redox reaction of peroxydisulfate with iodide has been used for many years as

part of the iodine clock reaction which introduces students to kinetics. If E°cell = 1.587 V and E° of the cathode half-cell is 0.536 V, what is E° of the anode half-cell?

S2O82–(aq) + 2H+ + 2I–(aq) 2HSO4

–(aq) + I2(aq)

4. Find the cell potential based on the following reduction half reaction at 250C if [Cd 2+ ] = 0.020 M and [Pb 2+ ] = 0.200 M. Given R = 8.314 J/mol.K, F= 96,485 J/V.mol

Cd 2+ + 2 e - → Cd E 0 = -0.403 V Pb 2+ + 2 e - → Pb E 0 = -0.126 V

5. Consider a galvanic cell that uses the reaction:

Cu (s) + 2Fe3+ (aq) → Cu2+ (aq) + 2Fe2+ (aq)

What is the potential of a cell at 25 °C that has the following ion concentrations? Given R = 8.314 J/mol.K, F= 96,485 J/V.mol

[Fe3+] = 1.0 x 10-4 M [Cu2+] = 0.25 M [Fe2+] = 0.20 M

PAST YEAR QUESTION

(Final Exam Sept 2013)

(Final Exam March 2014)

tutorial 2 – redox reaction

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