Question

@zale101

Answer 1

\(FAD + 2Cytc(Fe^{2+}) + 2 H+ --> FADH_2 + 2Cytc(Fe^{3+})\)

By looking at this equation, it is easier to determine what's being oxidized and what's not being oxidized. Fe2+ yields and creates Fe3+, which means Fe2+ lost one electron and became Fe3+.

Therefore, 2Cytc(Fe2+) is oxidized and is the reducing agent and FAD is reduced and is the oxidizing agent.
OILRIG - Oxidation is loss (of electrons) Reduction is Gain (of electrons)

FAD + 2 H+ + 2e- => FADH2 \(E^o=-0.040\)
cytochrome c (Fe^{3+}) +e => cytochrome c (Fe^{2+}) + \(E^o=0.235\)
I did a research and found the e cells for both of the equation.

FAD is the electron acceptor and cyt c(Fe2+) is the electron donor. That means Cytochrome c Fe3+ will have its e cel sign switch to negative because it is the electron donor.
Calculating E cell, we look at the process of solving it

\(\LARGE \Delta E^o=E_{e^- acceptor}-E_{e^- donor}\)

\(\large \Delta E^o=-0.040-(-0.235)=+0.195\)
E cell >0 (postive) which increases the chance of spontaneity

To determine the gibbs free energy, we use \(\Delta G^o = -nFΔE^o\)
every thing is a constant except \(n \) and \(\Delta E^o\)

n is the number of electrons used, which is 2 electron in both equation.

\(\Delta G^o = -(2)(96,480)(0.195)=-37627.2 J/mol\)

Answer: -37.627 kJ/mol

Answer 2

The Gibbs free energy is negative and the e cell is positive which indicate that this equation is a spontaneous reaction.