CBSE Class 10 Science 2019 · Paper 31/4/3 · Question 5

Ethanol is converted to ethanoic acid by heating it with alkaline potassium permanganate (or with acidified potassium dichromate), which acts as an oxidising agent: ${\text{CH}}_3{\text{CH}}_2\text{OH}+2[\text{O}]\stackrel{{\text{alkaline KMnO}}_4,\text{heat}}{\to }{\text{CH}}_3\text{COOH}+{\text{H}}_2\text{O}$ Justification: In this change ethanol (${\text{C}}_2{\text{H}}_6\text{O}$) gains an oxygen atom and loses two hydrogen atoms to become ethanoic acid (${\text{C}}_2{\text{H}}_4{\text{O}}_2$); the oxygen is supplied by the oxidising agent. Gain of oxygen (and loss of hydrogen) is oxidation, so the conversion of ethanol to ethanoic acid is an oxidation reaction.