Question

Calculate the standard free energy change (ΔG°) associated with the transfer of electrons from NADH and O2 using the following equation:

O2 + 2 NADH + 2H+ = 2 H20 + 2 NAD+
The half equations are : O2 + 4H + 4e- → 2H2O, E0' = 0.82V; NAD + H + 2e- → NADH, E0' = -0.32V

a) -250 kJ/mol
b) -110 kJ/mol
c) +250 kJ/mol
d) +110 kJ/mol

Answer 1

The standard free energy change associated with the transfer of electrons from NADH and O2 is -250 kJ/mol.

Step-by-step explanation:

To calculate the standard free energy change (ΔG°) associated with the transfer of electrons from NADH and O2, we can use the equation ΔG° = -nFE°. In this case, the half equations are:

O2 + 4H+ + 4e- → 2H2O, E° = 0.82V

NAD+ + H+ + 2e- → NADH, E° = -0.32V

Substituting the values into the equation, we get ΔG° = -nFE° = -(2)(96485C/mol)(0.13V) = -250 kJ/mol.

Therefore, the standard free energy change is -250 kJ/mol, so the answer is (a) -250 kJ/mol.