Which of the following reactions is an example of self oxidation and reduction?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Cannizzaro reaction
For example, methanal (no α-hydrogen) heated with concentrated potassium hydroxide gives methanol and potassium methanoate:
\( \displaystyle \ce{2HCHO + KOH} \xrightarrow[\text{conc.}]{\Delta} \ce{CH3OH + HCOOK} \)
NCERT (2026-27 edition):
8.4 Chemical Reactions – “(i) Cannizzaro reaction: Aldehydes which do not have an α-hydrogen atom, undergo self oxidation and reduction (disproportionation) reaction on heating with concentrated alkali. In this reaction, one molecule of the aldehyde is reduced to alcohol while another is oxidised to carboxylic acid salt.”