RI 18. Carbonyl Compounds Tutorial (Suggested Answers to Self-Check Questions)

-1- RAFFLES INSTITUTION YEAR 6 H2 CHEMISTRY 2026 Tutorial 18 Carbonyl Compounds Reaction Mindmaps  Aldehydes RCHOaldehydeR COHHHRCOHORCOO+ AgRCOO+ Cu2O R COHHCNHCOO+ CHI3NaNO2NNO2NHCRHK2Cr2O7(aq) / H2SO4(aq), heator KMnO4(aq) / H2SO4(aq), heatoxidationsilvermirrorTollens' reagent, warmoxidationreddish-brown pptFehling's solution, warmoxidationyellow pptI2(aq), NaOH(aq),warmoxidationorange ppt2,4-DNPHcondensationLiAlH4or H2, Ni catalystK2Cr2O7(aq), H2SO4(aq)heat with distillationoxidationreduction*Ethanal is the only aldehyde that has positive test (R=CH3) HCN, KCN catalystR COHHCH2NH2nucleophilic additionLiAlH4or H2, Ni catalystreductionR COHHCOOHH2SO4(aq), heatacidic hydrolysis*Positive test for ALLaldehydes*Positive test only for aliphatic aldehydes1o alcohol2,4-dinitrophenylhydrazonetri-iodomethanecyanohydrin Note: Alcohols with also give yellow ppt of CHI3 when warmed with I2(aq) and NaOH(aq)CHCH3OH

-2-  Ketones

-3- Answers to self-check questions Q1 OOOHOCHO(a)(b)(c)(d)(e)CH3CH2CCH2CH3OCH2CHOCH3CHCH3CH2CH2orOorC CCHOHCH3Hor Q2(a) LiAlH4 OR H2(g), Ni catalyst Q2(b) propanolK2Cr2O7(aq), H2SO4(aq)heat withdistillationpropanalKMnO4(aq),H2SO4(aq)heat (or heat under reflux)propanoic acidCH3CH2CH2OHCH3CH2CHOCH3CH2CO2H Heat propan-1-ol with acidified K2Cr2O7 carefully with 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