3. Using the data in the table below, Oxidant Reductant n | E,o (V) 2 -0.23 2+0.
ID: 717698 • Letter: 3
Question
3. Using the data in the table below, Oxidant Reductant n | E,o (V) 2 -0.23 2+0.82 Iml glutathione (oxidized) glutathione (reduced) 02 + 2H+ H2O Note: Eo is the standard redox potential at standard conditions. Eo refers to the partial reaction written as: oxidant + e- reductant a. Write the half reactions for the two reactions in the able. b. Write the overall reaction for the oxidation of reduced glutathione by O2 c. Calculate and AG" for this reaction. d. In which direction does the reaction proceed?Explanation / Answer
Part a
The two half cell reactions are
Oxidation reaction
Glutathione (reduced) = glutathione (oxidized) + 2e-
Eox = 0.23 V
Reduction reaction
1/2 O2 + 2H+ + 2e- = H2O
Ered = 0.82 V
Part b
Overall cell reaction
Glutathione (reduced) + 1/2 O2 + 2H+ + 2e- = H2O + glutathione (oxidized) + 2e-
Glutathione (reduced) + 1/2 O2 + 2H+ = glutathione (oxidized) + H2O
Part c
E° = Eox + Ered
= 0.23 + 0.82
= 1.05 V
G° = - nFE°
= - 2 x 96500 C/mol x 1.05 V
= - 202650 J/mol x 1kJ/1000 J
= - 202.65 kJ/mol
Part d
G° < 0
In the forward direction, the reaction proceeds