Question

The standard free energy change for a reaction can be calculated using the equation ΔG∘′=−nFΔE∘′ ΔG∘′=−nFΔE∘′ where nn is the number of electrons transferred, FF is Faraday's constant, 96.5 kJ·mol−1·V−1, and ΔE∘′ΔE∘′ is the difference in reduction potential. For each of the given reactions, determine the number of electrons transferred (n)(n) and calculate standard free energy (ΔG∘′)(ΔG∘′) . Consider the half-reactions and overall reaction for reaction 1. half-reactions:fumarate 2−+2H+CoQH2↽−−⇀succinate−↽−−⇀CoQ+2H+ half-reactions:fumarate−+2H+↽−−⇀succinate2−CoQH2↽−−⇀CoQ+2H+ overall reaction:fumarate2−+CoQH2↽−−⇀succinate2−+CoQΔE∘′=−0.009 V

Answer 1

Answer:

ΔG°′ = 1.737 KJ/mol

Explanation:

The reaction involves the transfer of two electrons in the form of hydride ions from reduced coenzyme Q, CoQH₂ to fumarae to form succinate and oxidized coenzyme Q, CoQ.

The overall equation of reaction is as follows:

fumarate²⁻ + CoQH₂ ↽⇀ succinate²⁻ + CoQ ;    ΔE∘′=−0.009 V

Using the equation  for standard free energy change; ΔG°′ = −nFΔE°′

where n = 2; F = 96.5 KJ.V⁻¹.mol⁻¹; ΔE°′ = 0.009 V

ΔG°′ = - 2 * 96.5 KJ.V⁻¹.mol⁻¹ * 0.009 V

ΔG°′ = 1.737 KJ/mol