RI Carbonyl Compound Tutorial - Answers to Self-check Questions

-1- RAFFLES INSTITUTION YEAR 6 H2 CHEMISTRY 2025 Tutorial 18 Carbonyl Compounds Reaction Mindmaps  Aldehydes R C H O aldehyde RC OH H H R C OH O R C O O + Ag R C O O + Cu 2O RC OH H CN H C O O + CH I3 Na N O2N NO2N H C R H K2Cr2O7(aq) / H2SO4(aq), heat or KMnO4(aq) / H2SO4(aq), heat oxidation silver mirror Tollens' reagent, heat oxidation reddish- brown ppt Fehling's solution, heat oxidation yellow ppt I2(aq), NaOH(aq), heat oxidation orange ppt 2,4-DNPH condensation LiAlH4 in dry ether or NaBH4 in methanol or H2/Ni, heat K2Cr2O7(aq), H2SO4(aq) heat with immediate distillation oxidation reduction *Ethanal is the only aldehyde that has positive test (R=CH 3) HCN,trace amt of KOH(aq) or HCN,trace amt of KCN(aq) or KCN(aq), H2SO4(aq) RC OH H CH2NH2 nucleophilic addition LiAlH4 in dry ether or H2/Ni, heat reduction RC OH H COOH H2SO4(aq), heat acidic hydrolysis *Positive test for ALL aldehydes *Positive test only for aliphatic aldehydes 1o alcohol 2,4-dinitrophenylhydrazone tri-iodomethane cyanohydrin

-2-  Ketones

-3- Answers to self-check questions Q1 Q2(a) LiAlH4 in dry ether, room temperature OR H2(g), Ni(s), heat OR NaBH4, room temperature Q2(b) Heat propan-1-ol with acidified K 2Cr2O7 carefully with immediate distillation of the product formed to collect mainly propanal as distillate. Q2(c) Observations: Orange ppt is formed. Answers to MCQ: 3) B 4) C 5) B 6) D 7) B