How does a SHE electrode work?
Does the $H_2$ gas get absorbed on the platinum electrode? How is it reduced? How are electrons transferred from the adsorbed gas to the solution? How is $H^+$ liberated or how does the $H^+$ in the solution take electrons from the adsorbed $H_2$?
If platinum doesn't adsorb the $H_2$ gas, what is its use? How does it provide a surface for reduction/oxidation of hydrogen?
Also in a concentration cell, why is it, in evaluating Q(reaction quotient) you take pressure of a gas numerically and put it directly as a concentration?
And in evaluating log(Q) in nernst equation, Q isn't always unitless. But inside log, you can put only a unitless number, isn't that so?
And in concentration cells, if [c1] > [c2], then c1 acts as cathode. In Gases, considering Pressure=k[C], where k is a constant fixed at a particular temperature. then in gas concentration cell opposite happens if pressure 1 > pressure 2 then pressure 1 part acts as anode.
What is P? is it pressure of the gas above the solution?
In net, how does a gas electrode work?