[123456789]

There is an electric cell (Copper and Mg electrodes immersed in FeSO4 soution, electrodes are connected by a wire)

What happens at the Cathode and Anode.

For the Anode, I know that Mg is much more reactive, so it's Mg :rarrow:Mg²⁺ +2e^-

However, at the anode, I wrote it was 2H⁺ +2e^-  H₂
And it's apparently wrong... The teacher said that though hydrogen is down the electrochemical series compared to Fe, it will not be liberated as it is an electric cell, so no H₂ (Something along those lines, which is why I still don't understand). Can someone kindly explain it to me?

However From a book, I have a counter example:(I hope it's clear enough)in the attachment

In this case, hydrogen can be liberated. Why is this so? Thank you.

[confusedstud]

Hmm I have been taught that hydrogen gas should also be evolved. So in her case iron should form instead of hydrogen gas?

[Vidya]

Hi
H+ has more reduction potential than Fe2+
so H+ will get reduced in H2 even in electric cell.I am not sure why your teacher is of different opinion.If the solution is molten FeSO4 in that case Fe will be formed.Are you sure that FeSO4 is aqueous solution in your question?

[123456789]

Seems like the previous post didn't appear?

Anyway original question below-maybe it's the wording of the question.

Look at part (a) cathode. And due to that (b) is wrong too...


EDIT: oh and also another question: How to calculate the standard reduction potential for such an electric cell? How to take the electrolyte into account? (at standard conditions, given a list of the reduction potentials) Thanks!

[confusedstud]

I think you are right though. Try and ask your teacher what is the explanation.