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Re: oxalic acid
> From: "roger" <roger at spinn_net>
> Subject: re: Oxalic Acid
> Paul Sears wrote:
> > Does anyone have a number for the standard electrode potential
> > for oxalate/CO2?
> I don't, but my old CRC Handbook gives the standard free energy of formation
> for oxalate ion and CO2 as -161.3 kcal/mole and -92.31 kcal/mole,
> respectively. From that the standard free energy for the reduction of CO2 to
> oxalate ion:
> 2(CO2) + 2e- -> 2(OOC-COO)-2
> is +23.32 kcal/mole. The corresponding standard reduction potential is +0.5
It doesn't work that way. The H+ + e- -> 1/2 H2 half cell
reaction is _defined_ as having a zero standard electrode potential,
so to go from free energies to standard potentials, we need the free
energy of reaction of the complete cell, oxalate/CO2 on one side
and H+/H2 on the other. The complete cell reaction would be:
H2 + 2CO2 -> H2C2O4(solution)
The free energy of _that_ reaction would give you the standard
> Good luck. Either yeast and sugar or bottled gas seems much easier.
I agree, but I'm glad to see some experimentation going on.
Paul Sears Ottawa, Canada