CBSE Class 12 · 2002 · All India Compartment · Aldehydes Ketones and Carboxylic AcidsShort Answer

(i) Acetal — from an aldehyde + 2 ROH: 1,1-diethoxyethane, CH${}_3$CH(OC${}_2$H${}_5$)${}_2$.
Oxime — from a carbonyl + NH${}_2$OH: acetaldoxime, CH${}_3$CH=NOH.
(ii) The phenyl's sp${}^2$ carbon pulls electrons (−I) and helps disperse the benzoate's charge, while acetic acid's methyl (+I) concentrates it — so C${}_6$H${}_5$COOH is the stronger acid (K${}_a$ 6.3×10${}^{-5}$ vs 1.8×10${}^{-5}$).