(a) Define the term functional group. Identify the functional group present in
(i) `H-overset(O)overset(||)(C)-H`
(ii) `H-underset(H)underset(|)overset(H)overset(|)(C)-overset(OH)overset(|)(C)=O`
(b) What happens when 5% alkaline `KMnO_(4)` solution is added drop by drop to warm ethanol taken in a test tube? State the role of alkaline `KMnO_(4)` solution in this reaction.

Explanation

(a) For the definition o functional group, The functional groups present in the compound are: Aldehydic (al) and carboxyl group (oic acid):
(b) Ethanol is oxidised to ethanoic acid. In tthis, dilute alkaline `KMnO_(4)` acts as an oxidising agent.
`underset("Ethanol")(CH_(3)CH_(2)OH)+underset("(released from oxidising agent)")(2(O))tounderset("Ethanoic acid")(CH_(3)COOH)+H_(2)O`