1. ALDEHYDES & KETONES

2. StructureStructure FormaldehydeAcetone AcetaldehydeAcetophenone Chlorahydrate Benzaldehyde HCHO or Aldehydes ketones

3. State Color Odor Physical properties Formaldehyde Acetaldehyde Acetone Chlorahydrate Benzaldehyde Acetophenone Liquid, mobile, solution Liquid, mobile, true Solid, crystalline Liquid, oily, true Colorless White Characteristic odor Bitter almond odor Pungent

4. Ignition test Inflammability Change in appearance Change in color flame Change in color Residue Comment Formaldehyde Acetaldehyde Acetone Chlorahydrate Benzaldehyde Acetophenone Inflammable, non luminous, non smoky Inflammable, luminous, smoky Non inflammable Volatilization Melting No change for all No residue for all No change for all Aliphatic Aromatic

5. Miscibility & Solubility H2OH2ODil. HCl10% NaOHConc. H 2 SO 4 Litmus paper Formaldehyde Acetaldehyde Acetone Chlorahydrate Benzaldehyde Acetophenone Miscible // Miscible // no change Miscible // Soluble // Immiscible in all Immiscible in all Comment All the compounds are neutral

6. Preliminary tests Formal.Acetal.Chlora.Benzal.AcetoneAcetoph. Soda lime test (for solid only) 30% NaOH On cold On hot Sweety odor of chloroform odor It is done for compound with no α hydrogen (( Self oxidation – reduction reaction)) Called Cannizzaro’s reaction All aromatic aldehyde & only formaldehyde goes cannizzaro’s reaction No reaction Not done On hot Dil. acetal.+ xss 30%NaOH Yellow resin + bad apple odor (( Called aldo condensation )) No α hydrogen Cannizzaro’s reaction No reaction Undergoes cannizzaro’s reaction Methanol + formic acid Sweety odor of chloroform odor + droplets of oil White ppt ((it is difficult to be done)) [Difficult to be done] (Acetone & Acetoph.)

7. Preliminary tests Formal.Acetal.Chlora.Benzal.Acetone Acetoph. FeCl 3 On cold On hot Conc. H 2 SO 4 On cold On hot No reaction No reaction for all Separation of an oily layer of Chloral Not done

8. General test of class: Reagent A For formaldehyde & ketones miscible in H 2 O For aliphatic {Formaldehyde, Acetaldehyde, Chlorahydrate, Acetone} Reagent B For aldehyde & ketones immiscible in H 2 O For aromatic {Benzaldehyde & Acetophenone} Aldehyde or ketones + 3 drops from reagent A or B shaking Yellow ppt Yellow– orange ppt No reaction Orange ppt Orange– yellow ppt Orange ppt Formal.Acetal.Chlora.Benzal.AcetoneAcetoph. 1] 2, 4 – dinitrophenyl hydrazine test:

9. General test of class: 2] Silver mirror test = Tollen’s reagent test = Ammonical silver nitrate test: Few ml of silver nitrate + 1 drop 10% NaOH Called Tollen’s reagent Black ppt of Ag 2 O + dil. NH 4 OH ((until clear solution obtained)) (1) 1ml of Tollen’s reagent + 1ml aldehyde or ketones [ heat on water bath 10 min.] cool on the rack (2) NOTE: NOTE: Reagent 1 st then aldehyde or ketones Formal. Acetal.Chlora.Benzal.Acetone Acetoph. No reaction Silver mirror after longer time on the water bath Rapidly gives silver mirror

10. General test of class: 3] Fehling reagent test = Fehling reduction test: Fehling A Fehling A Fehling B In test tube mix equal amount of Fehling A + Fehling B Blue color (1) In test tube few aldehyde or ketones + few Na 2 CO 3 + (Fehling A + B) (2) heat on water bath Formal. AcetaldehydeChlora.BenzaldehydeAcetone Acetophenone Rapidly change in colorChange in color take longer time No reaction