[IB1]

Hello everyone !


I've been thinking: What is the relation between the difference in electron affinity of two metals and the Voltage (potential difference) produced in the Voltaic cell of these two metals ?

I would expect there to be a linear relation between the differences in electron affinity and the Voltage produced, although I haven't checked this experimentally yet. I just think it makes sense to be like that ... but it's Chemistry so you never really know.

Thanks in advance for your replies.

[DevaDevil]

electron affinity of 2 metals??

electron affinity is the energy change when the atom accepts an electron to form an anion. Metals generally donate electrons to form cations...

[rabolisk]

I would compare ionization energies and standard electrode potential rather than electron affinity and potential.

[DevaDevil]

element  |ionization energy (eV) of 1st electron  |reduction potential for reaction (V v RHE)

Li       |5.392           |-3.045
Na      |5.139          |-2.71
Mg     |7.646          |-2.375 (2e^-)
Al      |5.986           |-2.3
K       |4.341           |-2.94
Ca      |3.113          |-3.02
Mn     |7.435          |-1.029 (2e^-)
Fe      |7.870           |-0.409 (2e^-)
Co      |7.86            |-0.28 (2e^-)
Ni       |7.635           |-0.23 (2e^-)
Cu      |7.72            |0.522
Zn      |9.394           |-0.763 (2e^-)


good luck finding a trend there, thing is: the reduction energy is in aqueous solution, the ionization energy in vacuum. They are very different

[IB1]

Thanks for replying.

Is there any way to switch from aqueous solutions to non-aqueous ones, because clearly the redox reaction in the Voltaic cell doesn't happen in aqueous solution ?

[Edit: I'm talking here about the reduction potential in non-aqueous solutions]