JEE Main · 2022 · 27 Jul 2022 · Shift 1 · Redox Reactions and Electrochemistry

In the titration of

KMnO_{4}

and oxalic acid in acidic medium, the change in oxidation number of carbon at the end point is ____

Answer: 1

Solution

In oxalic acid

H_{2} C_{2} O_{4}

, the oxidation state of carbon is +3. When oxidized by

KMnO_{4}

in acidic medium, oxalic acid is converted to

CO_{2}

, where carbon has an oxidation state of +4. The change in oxidation number per carbon atom is

+ 4 - (+ 3) = + 1

. Therefore, the change in oxidation number of carbon is 1.

JEE Main · 2022 · 27 Jul 2022 · Shift 1 · Integer answer