WBJEE 2025 Physics and Chemistry Papers

Let's break down how molecular oxygen (O2) is reduced step-by-step:
Adding one electron to O2 gives the superoxide ion:
O2+e−⟶O2∙−
(This is a one-electron reduction.)
Adding a second electron gives the peroxide ion:
O2+2e−⟶O22−
(This is a two-electron reduction.)
When O2 undergoes a four-electron reduction, the process is:
O2+4e−⟶2O2−
Here, each oxygen atom ends up as an oxide ion ( O2− ).
So, the four-electron reduced form of O2 is oxide, which corresponds to Option C .