Question

What is the four-electron reduced form of O$_2$?

• A. Superoxide
• B. Peroxide
• C. Oxide
• D. Ozone

Hint:

Using a simple frame or just bolding for the box Key Points: O$_2$ (Oxygen): Oxidation State = 0 O$_2^-$ (Superoxide): Oxidation State = -1/2 (average) O$_2^{2-$ (Peroxide): Oxidation State = -1 O$^{2-$ (Oxide): Oxidation State = -2 Four-electron reduction of O$_2$ (2 atoms) means each atom gains 2 electrons, forming 2 O$^{2-$ ions. Ozone (O$_3$) is an allotrope, not a simple reduction product.