What is the half-cell reactions in a hydrogen fuel cell, and calculate the standard voltage at 25°C

Question

H2(g)+ O2(g)------>2H2O(l)

Answer 1

I think you made a typo. The reaction I think, is 2H2 + O2 ==> 2H2O
H2 ==> 2H^+ + 2e Eo = ??
O2 + 4H^+ + 4e Eo = +1.229

Eocell = ??

Answer 2

Thank you so much