One way methane is produced is via reduction of carbon dioxide, which serves as electron acceptor, with molecular hydrogen, which serves as electron donor.

a. Write a balanced stoichiometric equation for the above stated process and calculate the reaction standard free-energy change (delta G^0') based on free energies of formation (G_f^0)

b. When the pressure of the carbon dioxide and methane is 0.80 atm and 0.65 atm, respectively, calculate the minimum molecular hydrogen (H2) concentration (atm) required in order the actual free-energy change (delta G) to be at least equal to the above calculated standard free-energy change (delta G^0')

c. For teh same process, i.e., methance production via CO2 reducition with H2, calculate the reaction standard free-energy change (delta G^0') based on reduction potentials.