Question

Calculate the standard cell emf for galvanic
cells with the cell reaction
2 H2(g) + O2(g) → 2 H2O(ℓ)
in acidic solution.
Answer in units of V.

What is the standard reaction free energy?
Faraday’s constant is 96485 C/mol.
Answer in units of kJ/mol.

I got 1.23 V for the first one

Answer 1

I did not check you 1.25 v but if you post your work I'll check it. For the other part use dGo = -nEoF
n = 4

Answer 2

I got -474706.2 kJ/mol but it's saying it's wrong

Answer 3

I assume you are checking into a data base. A common problem with these is that you are reporting too many significant figures. Since your V is to 3 s.f. I would keep the reporting to 3 s.f. Second, the problem asks for kJ/mol. Your -4.75E5 kJ is for the reaction and that is for 2 mols. So divide by 2.
-4.747062E5/2 = -2.37031E5 kJ/mol which I would round to -2.37 kJ/mol.



4.