What is the standard cell potential of a batter made from th

What is the standard cell potential of a batter made from the half reactions: 2H+ + 2e- ---> H_2 (E = 0V) & O_2 + 4H+ + 4e- ---> 2H2O (E = +1.23V). I know how to get to the answer which is 1.23, could someone show me how to tell the difference between the anode and the cathode. Please show work.

Solution

For a galvanic cell, the total cell potential must be positive.
E(cell) = E(reduction) - E(oxidation)

In a galvanic cell, oxidation occurs at the anode and reduction at the cathode (Way to remember: Anode and Oxidation both begin with vowels and Reduction and Cathode both beging with consenants)

in this case, the 2nd half reaction is where the reduction takes place, and 1st reaction depicts oxidation. Hence your answer is E=1.23-0= 1.23v