My text book says that standard conditions used in electrochemical cells are 1 mol dm-3 of each solution. However, it also says that the electrode potential depends on the pressure, temperature and concentration of reactants.
After this it states that if the oxidising agent has a concentration greater than 1 mol dm-3 then it is more likely to favour reduction and the electrode potential would be more positive than the standard electrode potential.
Can someone explain why this is?
So that's 298k and blah blah blah
But if you think of the cell as a set of reversible reactions, then by le chateliers principle, if you change the concentration so that you affect how the reaction will occur, then more reaction will go towards the reduction. That means the reduction is more likely to occur, hence a higher reduction potential (voltage).
Failing that, I always remember it as: EMF= RED - OXI therefore if Oxi goes down, and Red goes up, EMF must also go up.
Hope that helps a bit