14.11d

[Kayla Ikemiya 1E]

How do you come up with the oxidizing half reduction? Why is H+ on the same side as the O2?

[RuchaDeshpande1L]

Figuring out why H+ was on the same side as O2 confused me at first too! However, when we attempt to balance the half-reaction for the anode, we can see that 5 H+ ions are needed on the left side to balance the number of hydrogen atoms on both sides. We now have 5 H+ on the left and 2H2O and H+ on the right. Because we have H+ on both sides of our balanced equation, we can cancel them to obtain a final half reaction of: 4H+ + 4e- + O2 --> 2H2O. In addition, we need to remember to flip the anode half-reaction. This is because oxidation is occurring at this electrode, and we need the electrons to be on the products side. I hope this helped!