- Aldehyde R-CHO at end one H formaldehyde HCHO formalin 40% preservative biology specimens dead frogs pungent acetaldehyde CH3CHO fruity ripe fruits ketone R-CO-R middle two alkyl acetone CH3COCH3 propanone nail polish remover super solvent evaporates fast cleans glue paint grease carboxylic R-COOH carbonyl+OH -COOH acetic 5% vinegar kitchen salad pickles sour formic ant sting burning C=O polar C delta+ O delta- electrophilic attacked by nucleophile magnet hungry.
- IUPAC -al methanal formaldehyde ethanal acetaldehyde benzaldehyde almond -one propanone acetone butan-2-one MEK acetophenone -oic acid methanoic formic ethanoic acetic benzoic preservative structure sp2 trigonal planar 120 planar flat boiling higher than alkanes polar dipole-dipole lower than alcohols no H-bonding between themselves propanone 56 ethanol 78 acetaldehyde 20 benzaldehyde 179 phenyl higher small soluble water H-bond carbonyl O accepts H from water formaldehyde fully soluble larger less soluble non-polar dominates flat triangle no hands holding.
- Preparation alcohols oxidation PCC mild aldehyde stops Jones strong acid over oxidation primary to aldehyde acid secondary to ketone tertiary no alpha H no oxidation ozonolysis alkene O3 Zn H2O cleaves double bond carbonyls ethene 2 formaldehyde propene acetaldehyde+formaldehyde alkyne hydration H2O Hg2+ H2SO4 Markovnikov ketone ethyne acetaldehyde propyne acetone Rosenmund acid chloride RCOCl+H2 Pd BaSO4 poisoned aldehyde stops CH3COCl to CH3CHO half cooking stops Friedel-Crafts acylation benzene+RCOCl AlCl3 ArCOR aryl ketone acetophenone decorating cake aromatic ketone different cooking methods grilling cutting bridge.
- Physical boiling formaldehyde gas acetaldehyde 20 liquid acetone 56 benzaldehyde 179 phenyl higher nucleophilic addition main reaction C delta+ attacked Nu- tetrahedral alkoxide intermediate protonation addition product planar both sides attack magnet attack open umbrella proton closes Grignard RMgX+HCHO primary alcohol RCHO secondary R2CO tertiary new C-C bond building bigger Lego connecting blocks HCHO primary RCHO secondary R2CO tertiary CH3MgBr HCHO ethanol primary formaldehyde acetaldehyde secondary acetone tertiary HCN cyanohydrin CN+OH same C toxic lab only NaHSO3 bisulfite white crystalline reversible purify separate aldehydes ketones white precipitate test purify.
- Important aldol alpha H dilute NaOH beta-hydroxy aldol heat dehydration alpha beta unsaturated conjugated stable two same friends join hands enolate attacks another carbonyl bigger beta-hydroxy loses water conjugated acetaldehyde crotonaldehyde CH3CH=CHCHO acetone mesityl oxide (CH3)2C=CHCOCH3 cross aldol two different mixture Cannizzaro no alpha H conc NaOH disproportionation one oxidized acid salt one reduced alcohol sharing conc NaOH 2HCHO methanol formate 2 benzaldehyde benzyl alcohol benzoate no alpha H friends one gives electrons oxidized acid other reduced alcohol haloform CH3CO or CH3CH(OH) I2 NaOH CHI3 yellow ppt methyl ketones secondary alcohols ethanol positive yellow flag methyl ketone present ethanol positive test distinguishes oxidation aldehyde easily acid Tollen [Ag(NH3)2]+ silver mirror black Ag aldehyde yes ketone no Fehling Cu2+ blue Cu2O red ppt aliphatic aldehyde not aromatic ketone no ketone strong oxidizer breaks C-C mixture acids reduction LiAlH4 NaBH4 aldehyde primary secondary ketone secondary H2 Ni also Wolff-Kishner NH2NH2 KOH high temp Clemmensen Zn Hg conc HCl C=O to CH2 alkane acetone to propane removal O to CH2 alkane propane Tollen silver mirror distinguishing lab haloform yellow ppt methyl ketones lab formalin preservative.
- Carboxylic preparation primary alcohol Jones acid aldehyde oxidation Tollen Fehling Jones acid nitrile RCN hydrolysis acid base H2O H+ OH- RCOOH amide intermediate acetonitrile acetic acid Grignard CO2 RMgX+CO2 dry ether H3O+ RCOOH builds one carbon more methylmagnesium bromide+CO2 acetic acid over oxidation hydrolysis builds one C more physical dimer H-bonding 8-membered ring double H-bond double handshake stronger higher boiling than alcohols similar mass acetic 118 ethanol 78 small soluble water H-bond larger less soluble non-polar dominates acidity stronger than phenol alcohol resonance carboxylate COO- two equivalent negative delocalized two O very stable sharing burden more stable stronger acid EW NO2 Cl increase ClCH2COOH stronger than CH3COOH ED CH3 decrease order CF3COOH strongest 3 F EW CCl3COOH HCOOH CH3COOH phenol weaker alcohol weaker NaHCO3 CO2 bubbles effervescence test RCOOH+NaHCO3 COONa+H2O+CO2 distinguishes phenol no bubbles NaOH salt COONa+H2O esterification RCOOH+R'OH conc H2SO4 heat RCOOR' ester+H2O Fischer fruity marriage fruity child water acetic+ethanol ethyl acetate fruity nail polish remover also decarboxylation RCOONa+NaOH CaO heat RH+Na2CO3 removes CO2 Kolbe electrolysis RCOONa electrolysis R-R higher alkane.
- Derivatives acid chloride RCOCl RCOOH+SOCl2 Darzens best SO2+HCl gases escape pure RCOOH+PCl5 RCOCl+POCl3+HCl very reactive hydrolyzes water RCOCl+H2O RCOOH+HCl fumes HCl used aldehydes ketones esters amides aggressive fumes ester RCOOR' Fischer acid+alcohol H2SO4 heat reversible fruity smell acetic+ethanol ethyl acetate fruity nail polish remover solvent hydrolysis acid base acid+alcohol saponification base soap RCOOR'+NaOH RCOONa soap+R'OH alcohol fats triglyceride ester+NaOH glycerol+soap fatty acid Na salt soap glycerol fats NaOH soap amide RCONH2 RCOOH+NH3 heat acetamide dehydration P2O5 nitrile RCN hydrolysis acid back stable nylon 6,6 polyamide adipic acid+hexamethylenediamine condensation polyester PET terephthalic acid+ethylene glycol clothes bottles family aggressive fumes fruity pleasant soap stable nylon clothes PET bottles everyday clothes bottles.
- Everyday formalin 40% formaldehyde HCHO aqueous preservative biology specimens dead frogs fishes rotting disinfectant sterilizes equipment strong preservative handle carefully gloves pungent acetone CH3COCH3 nail polish remover super solvent cleans glue paint grease evaporates fast flammable ventilated solvent paints varnishes acetaldehyde CH3CHO ripe fruits coffee bread fruity aroma flavoring benzaldehyde C6H5CHO almond smell almond essence perfumes acetic acid vinegar 5% CH3COOH kitchen cooking dressings marinades pickling crunchy salads tasty natural cleaning grease limescale food safe tangy glacial 100% pure solidifies ice below 16.6 citric acid lemon sour fresh zing lemonade sweets descale kettles stains natural preservative jams candies benzoic acid preservative foods drinks juices soda packaged prevents mold bacteria aspirin pain reliever headaches fever inflammation skincare exfoliation lactic acid CH3CH(OH)COOH sour milk muscle pain exercise formic ant sting burning industrial acetone solvent acetic acid cellulose acetate photographic film vinyl acetate polyvinyl acetate adhesive Fevicol museum preserving past eraser removes polish quickly kitchen magic makes pickles crunchy tasty lemon fresh zing guard prevents mold bacteria helper headache fever everywhere carbonyls.
Chapter 8 - Aldehydes, Ketones and Carboxylic Acids
Beginner
Topper
1. Introduction - Carbonyl Family - Smell of Vanilla and Nail Polish
Walk into a bakery you smell vanilla - that is vanillin an aldehyde. Open nail polish remover - sharp smell acetone a ketone. Taste sour lemon - citric acid a carboxylic acid. All have carbonyl C=O.
Aldehyde R-CHO: carbonyl C double bonded O and one H at end of chain. Simplest formaldehyde HCHO used as formalin 40% preservative for biology specimens in school lab you saw jars with dead frogs preserved that pungent smell formaldehyde. Acetaldehyde CH3CHO present in ripe fruits gives fruity smell.
Ketone R-CO-R: carbonyl in middle between two alkyl groups. Simplest acetone CH3COCH3 propanone you use to remove nail polish evaporates quickly super solvent cleans glue paint grease.
Carboxylic acid R-COOH: carbonyl plus OH together -COOH carboxyl. Acetic acid CH3COOH 5% in vinegar you use in kitchen salad dressing pickles makes crunchy sour. Formic acid HCOOH in ant sting causes burning.
Carbonyl C=O is polar C delta+ O delta- oxygen more electronegative pulls electrons. So carbon is electrophilic attacked by nucleophile.
Visual Learning Method: Bakery vanilla vanillin aldehyde, nail polish remover acetone ketone, lemon vinegar carboxylic acid, formaldehyde formalin 40% jar specimens, acetaldehyde fruity, C=O polar C delta+ O delta- electrophilic, kids Wow!
Daily Analogy: Carbonyl like magnet O negative side pulls electrons C positive side hungry for electrons attacked by nucleophile. Aldehyde at end like tail with H, ketone in middle like bridge between two groups, carboxylic acid combined carbonyl plus OH sour taste.
Introduction - Carbonyl Family
Revision Points - Easy:
- Aldehyde R-CHO at end one H formaldehyde formalin 40% preservative biology specimens.
- Ketone R-CO-R in middle two alkyl acetone nail polish remover super solvent evaporates fast.
- Carboxylic R-COOH acetic acid 5% vinegar kitchen sour pickles formic ant sting.
- C=O polar C delta+ O delta- C electrophilic attacked by nucleophile.
2. Nomenclature & Structure - Naming Like Family
IUPAC aldehyde suffix -al methanal HCHO formaldehyde, ethanal CH3CHO acetaldehyde, benzaldehyde C6H5CHO almond smell. Ketone suffix -one propanone CH3COCH3 acetone, butan-2-one CH3COCH2CH3 methyl ethyl ketone MEK industrial solvent, acetophenone C6H5COCH3. Carboxylic acid suffix -oic acid methanoic acid HCOOH formic acid, ethanoic acid CH3COOH acetic acid vinegar, benzoic acid C6H5COOH preservative.
Structure carbonyl carbon sp2 trigonal planar 120 degrees planar flat. Aldehyde and ketone have no H-bonding between themselves no O-H so boiling point higher than alkanes due to polar dipole-dipole but lower than alcohols which H-bond. Example propanone 56 C boiling ethanol 78 C similar mass alcohol higher due to H-bond. Small aldehydes ketones soluble in water due to H-bond with water O of carbonyl accepts H from water H-bond small R soluble formaldehyde fully soluble, larger chain solubility decreases non-polar dominates.
Visual Learning Method: IUPAC -al methanal ethanal benzaldehyde almond, -one propanone acetone butan-2-one MEK acetophenone, -oic acid methanoic formic ethanoic acetic benzoic preservative, sp2 120 planar, boiling propanone 56 ethanol 78 no H-bonding vs H-bonding, solubility small soluble formaldehyde fully.
Daily Analogy: Sp2 planar like flat triangle 120 degrees. H-bonding like holding hands alcohols hold hands each other higher boiling carbonyl no hands between themselves lower boiling but can hold hands with water small soluble.
Nomenclature & Structure
Revision Points - Easy:
- Aldehyde -al methanal formaldehyde ethanal acetaldehyde benzaldehyde almond.
- Ketone -one propanone acetone butan-2-one MEK acetophenone.
- Carboxylic -oic acid methanoic formic ethanoic acetic vinegar benzoic preservative.
- Structure sp2 planar 120 degrees flat.
- Boiling higher than alkanes polar lower than alcohols no H-bonding between themselves propanone 56 ethanol 78.
- Small soluble water H-bond with water formaldehyde fully soluble larger less soluble.
3. Preparation of Aldehydes & Ketones - Making from Scratch
From alcohols: primary alcohol RCH2OH oxidation with PCC pyridinium chlorochromate mild gives aldehyde RCHO stops not over oxidized. Strong oxidation Jones CrO3 H2SO4 gives acid over oxidizes. Secondary alcohol R2CHOH oxidation PCC or Jones both give ketone R2CO. Tertiary no alpha H no oxidation.
From alkenes: ozonolysis alkene + O3 then Zn H2O cleaves double bond gives carbonyls. Example ethene CH2=CH2 ozonolysis gives 2 formaldehyde HCHO. Propene CH3CH=CH2 gives acetaldehyde CH3CHO + formaldehyde.
From alkynes: hydration alkyne + H2O Hg2+ H2SO4 Markovnikov gives ketone. Ethyne HCCH gives acetaldehyde CH3CHO, propyne CH3CCH gives acetone CH3COCH3.
Rosenmund reduction: acid chloride RCOCl + H2 Pd BaSO4 poisoned catalyst gives aldehyde RCHO stops not to alcohol. Example CH3COCl -> CH3CHO.
Friedel-Crafts acylation: benzene C6H6 + RCOCl AlCl3 -> alkyl aryl ketone ArCOR. Example benzene + CH3COCl -> acetophenone C6H5COCH3. Important for aromatic ketones.
Daily: PCC oxidation lab preparation, ozonolysis used to find position of double bond.
Visual Learning Method: Alcohol oxidation PCC aldehyde Jones acid over oxidation secondary ketone tertiary no oxidation, ozonolysis O3 Zn H2O cleaves ethene 2 formaldehyde, alkyne hydration Hg2+ ketone ethyne acetaldehyde propyne acetone, Rosenmund RCOCl H2 Pd BaSO4 aldehyde, Friedel-Crafts benzene RCOCl AlCl3 acetophenone.
Daily Analogy: Preparation like different cooking methods: oxidation removes H adds O like grilling, ozonolysis cuts double bond like cutting bridge, Rosenmund reduces chloride to aldehyde gentle reduction stops early like half cooking, Friedel-Crafts adds acyl to benzene like decorating cake aromatic ketone.
Preparation of Aldehydes & Ketones
Revision Points - Easy:
- Primary alcohol PCC aldehyde Jones acid over oxidation secondary ketone tertiary no oxidation.
- Ozonolysis alkene O3 Zn H2O cleaves to carbonyls ethene 2 HCHO.
- Alkyne hydration Hg2+ H2SO4 Markovnikov ketone ethyne acetaldehyde propyne acetone.
- Rosenmund acid chloride + H2 Pd BaSO4 aldehyde stops.
- Friedel-Crafts acylation benzene + RCOCl AlCl3 aryl ketone acetophenone.
4. Physical Properties & Nucleophilic Addition - Core Reaction
Boiling point as earlier higher than alkanes polar dipole-dipole lower than alcohols no H-bonding between themselves. Formaldehyde gas, acetaldehyde liquid low boiling 20 C, acetone 56 C, benzaldehyde 179 C higher due to phenyl.
Main chemical reaction nucleophilic addition: C delta+ attacked by nucleophile Nu- gives tetrahedral alkoxide intermediate then protonation gives addition product. Because carbonyl planar Nu can attack from both sides.
Examples: Grignard RMgX + R'CHO aldehyde gives secondary alcohol R'CH(OH)R after H2O/H+ workup, RMgX + R'COR'' ketone gives tertiary alcohol R'R''C(OH)R forms new C-C bond very important for building bigger molecules. Example CH3MgBr + HCHO formaldehyde -> CH3CH2OH ethanol primary via secondary? Actually HCHO + CH3MgBr gives ethanol primary? Wait formaldehyde + Grignard gives primary, acetaldehyde gives secondary, acetone gives tertiary. Correct: HCHO + RMgX primary, RCHO secondary, R2CO tertiary.
HCN addition: R2C=O + HCN -> R2C(OH)CN cyanohydrin CN and OH on same carbon. HCN toxic lab only. NaHSO3 bisulfite addition R2C=O + NaHSO3 -> R2C(OH)SO3Na crystalline white precipitate used to purify separate aldehydes ketones reversible with acid base.
Daily: Grignard builds alcohols lab important, bisulfite test white precipitate distinguishes aldehydes ketones from other compounds.
Visual Learning Method: Boiling formaldehyde gas acetaldehyde 20 acetone 56 benzaldehyde 179, nucleophilic addition C delta+ Nu- tetrahedral intermediate both sides attack, Grignard HCHO primary RCHO secondary R2CO tertiary new C-C bond, HCN cyanohydrin, NaHSO3 white crystalline reversible purification.
Daily Analogy: Nucleophilic addition like magnet attack positive carbon hungry C delta+ nucleophile negative magnet sticks forms tetrahedral intermediate like open umbrella then proton closes umbrella addition product. Grignard building C-C bond like Lego connecting blocks builds bigger alcohol.
Physical Properties & Nucleophilic Addition
Revision Points - Easy:
- Boiling higher than alkanes polar lower than alcohols no H-bonding between themselves.
- Formaldehyde gas acetaldehyde 20 C acetone 56 C benzaldehyde 179 C phenyl higher.
- Nucleophilic addition main reaction C delta+ attacked by Nu- tetrahedral intermediate then protonation.
- Grignard HCHO primary alcohol RCHO secondary R2CO tertiary new C-C bond building bigger.
- HCN cyanohydrin CN+OH same carbon toxic lab only.
- NaHSO3 white crystalline reversible used to purify separate aldehydes ketones.
5. Important Reactions - Aldol Cannizzaro Haloform Oxidation Reduction
Aldol condensation: aldehyde ketone with alpha hydrogen CH3CO- + dilute NaOH gives beta-hydroxy carbonyl aldol then heat dehydration gives alpha beta unsaturated carbonyl conjugated. Example acetaldehyde 2CH3CHO dilute NaOH -> CH3CH(OH)CH2CHO 3-hydroxybutanal aldol then heat -> CH3CH=CHCHO crotonaldehyde conjugated double bond carbonyl stable. Ketone also acetone 2CH3COCH3 dilute NaOH -> (CH3)2C(OH)CH2COCH3 diacetone alcohol then heat -> (CH3)2C=CHCOCH3 mesityl oxide. Cross aldol two different carbonyls mixture products.
Cannizzaro: aldehyde with no alpha H like formaldehyde HCHO benzaldehyde C6H5CHO + conc NaOH gives disproportionation one oxidized to acid salt and one reduced to alcohol. Example 2HCHO + NaOH -> CH3OH methanol + HCOONa sodium formate. 2C6H5CHO + NaOH -> C6H5CH2OH benzyl alcohol + C6H5COONa sodium benzoate. No alpha H required.
Haloform test: CH3CO- group or CH3CH(OH)- gives CHI3 yellow precipitate with I2 NaOH. Reaction CH3COCH3 + I2 NaOH -> CHI3 iodoform yellow ppt + CH3COONa. Used to test methyl ketones and secondary alcohols with CH3CH(OH)- ethanol gives positive. Example ethanol CH3CH2OH I2 NaOH -> CHI3 yellow ppt positive test distinguishes ethanol.
Oxidation: aldehyde oxidized easily to acid by Tollen's reagent [Ag(NH3)2]+ silver mirror test aldehyde gives Ag mirror black precipitate ketone no. Fehling's solution Cu2+ blue gives Cu2O red precipitate with aldehyde aliphatic not aromatic ketone no. Ketone does not oxidize easily needs strong oxidizer breaks C-C bond gives mixture acids. Carboxylic acids from aldehyde oxidation.
Reduction: aldehyde ketone reduction LiAlH4 NaBH4 gives alcohol primary secondary respectively, H2 Ni also. Wolff-Kishner NH2NH2 KOH high temp and Clemmensen Zn Hg conc HCl both reduce C=O to CH2 alkane removes oxygen. Example CH3COCH3 acetone -> CH3CH2CH3 propane via both methods.
Daily: Tollen silver mirror test used to distinguish aldehyde ketone school lab, haloform iodoform yellow ppt test for methyl ketones in lab, formalin preservative.
Visual Learning Method: Aldol alpha H dilute NaOH beta-hydroxy then dehydration alpha beta unsaturated crotonaldehyde mesityl oxide, Cannizzaro no alpha H conc NaOH disproportionation methanol formate benzyl alcohol benzoate, Haloform CH3CO I2 NaOH CHI3 yellow ppt methyl ketones secondary alcohols ethanol positive, Tollen Ag(NH3)2 silver mirror black Ag aldehyde Fehling blue to red Cu2O, Wolff-Kishner NH2NH2 KOH Clemmensen Zn Hg HCl C=O to CH2 propane.
Daily Analogy: Aldol like two same friends join hands alpha H deprotonated enolate attacks another carbonyl makes bigger beta-hydroxy then loses water becomes conjugated stable. Cannizzaro like two identical no alpha H friends one gives up electrons oxidized acid other takes reduced alcohol sharing in conc NaOH. Haloform like cutting CH3CO group with I2 gives yellow CHI3 precipitates like yellow flag methyl ketone present. Tollen silver mirror like aldehyde polishes silver mirror ketone cannot.
Important Reactions - Aldol Cannizzaro Haloform
Revision Points - Easy:
- Aldol alpha H dilute NaOH beta-hydroxy carbonyl then heat alpha beta unsaturated conjugated acetaldehyde crotonaldehyde acetone mesityl oxide.
- Cannizzaro no alpha H conc NaOH disproportionation one oxidized acid salt one reduced alcohol HCHO methanol formate benzaldehyde benzyl alcohol benzoate.
- Haloform CH3CO or CH3CH(OH) I2 NaOH CHI3 yellow ppt methyl ketones secondary alcohols ethanol positive test.
- Oxidation aldehyde easily acid Tollen Ag(NH3)2 silver mirror black Ag aldehyde yes ketone no Fehling Cu2+ blue to red Cu2O aliphatic aldehyde not aromatic.
- Reduction LiAlH4 NaBH4 aldehyde primary secondary ketone secondary Wolff-Kishner NH2NH2 KOH high temp Clemmensen Zn Hg HCl C=O to CH2 alkane acetone to propane.
6. Carboxylic Acids - Preparation and Properties - Sour Taste
Preparation: primary alcohol RCH2OH oxidation Jones CrO3 H2SO4 or KMnO4 acidic gives RCOOH acid over oxidation. Aldehyde RCHO oxidation Tollen Fehling Jones gives RCOOH. Nitrile RCN hydrolysis acid or base H2O H+ or OH- gives RCOOH amide intermediate then acid. Example CH3CN acetonitrile hydrolysis -> CH3COOH acetic acid. Grignard CO2: RMgX + CO2 dry ether then H3O+ gives RCOOH carboxylic acid builds one carbon more. Example CH3MgBr + CO2 -> CH3COOH acetic acid.
Physical: carboxylic acids H-bonding dimer forms two molecules H-bonded 8-membered ring double H-bond so higher boiling than alcohols similar mass due to dimer. Example acetic acid boiling 118 C ethanol 78 similar mass but acid higher due to dimer H-bonding. Solubility small acids fully soluble H-bond with water formic acetic propionic soluble larger decreases non-polar dominates.
Acidity: carboxylic acids acidic stronger than phenol alcohol due to resonance stabilized carboxylate COO- two equivalent structures negative delocalized on two O very stable. Electron withdrawing groups NO2 Cl increase acidity stronger acid ClCH2COOH chloroacetic stronger than CH3COOH, electron donating CH3 decrease acidity. Acidity order: CF3COOH strongest due to 3 F strong EW, then CCl3COOH, then HCOOH formic, then CH3COOH acetic. Phenol weaker than carboxylic alcohol weaker than phenol neutral.
Reactions: acid gives CO2 with NaHCO3 effervescence test carboxylic acid + NaHCO3 -> COONa + H2O + CO2 bubbles distinguishes from phenol which no bubbles. With NaOH gives salt COONa + H2O. Esterification RCOOH + R'OH conc H2SO4 heat -> RCOOR' ester + H2O Fischer fruity smell esters. Example acetic acid + ethanol -> ethyl acetate CH3COOCH2CH3 fruity smell nail polish remover also. Decarboxylation RCOONa + NaOH CaO heat -> RH + Na2CO3 removes CO2 Kolbe electrolysis RCOONa electrolysis gives R-R alkane higher.
Visual Learning Method: Prep alcohol oxidation Jones acid, aldehyde oxidation, nitrile hydrolysis RCN to RCOOH, Grignard CO2 builds one C more, dimer H-bonding 8-membered ring double H-bond higher boiling acetic 118 ethanol 78, acidity carboxylate resonance two O delocalized EW increases ClCH2COOH stronger, NaHCO3 CO2 bubbles test, NaOH salt, esterification RCOOH+R'OH H2SO4 ester fruity ethyl acetate, decarboxylation RCOONa+NaOH CaO RH+Na2CO3, Kolbe electrolysis R-R.
Daily Analogy: Dimer H-bonding like two friends holding both hands double handshake stronger higher boiling. Acidity like after donating H+ carboxylate has two O sharing negative like two friends sharing burden more stable stronger acid. Esterification like marriage acid + alcohol with H2SO4 priest gives ester fruity child + water.
Carboxylic Acids - Preparation Properties
Revision Points - Easy:
- Prep primary alcohol Jones oxidation acid aldehyde oxidation Tollen Fehling Jones acid nitrile hydrolysis RCN->RCOOH Grignard CO2 RMgX+CO2->RCOOH builds one C more CH3MgBr+CO2 acetic acid.
- Dimer H-bonding 8-membered ring double H-bond higher boiling than alcohols acetic 118 ethanol 78.
- Small soluble water H-bond larger less soluble non-polar dominates.
- Acidity stronger than phenol alcohol resonance carboxylate two O delocalized very stable EW NO2 Cl increase acidity ClCH2COOH stronger than CH3COOH ED CH3 decrease.
- Order CF3COOH strongest CCl3COOH HCOOH CH3COOH phenol weaker alcohol weaker.
- NaHCO3 CO2 bubbles effervescence test distinguishes phenol no bubbles NaOH salt esterification acid+alcohol H2SO4 ester fruity ethyl acetate decarboxylation RCOONa+NaOH CaO RH+Na2CO3 Kolbe electrolysis R-R higher alkane.
7. Carboxylic Acid Derivatives - Esters Acid Chlorides Amides
Derivatives formed from carboxylic acid OH replaced.
Acid chloride RCOCl: preparation RCOOH + SOCl2 thionyl chloride -> RCOCl + SO2 + HCl gases escape Darzens best pure RCOOH + PCl5 -> RCOCl + POCl3 + HCl. Very reactive hydrolyzes water back to acid RCOCl+H2O->RCOOH+HCl fumes HCl. Used to make aldehydes ketones esters amides.
Ester RCOOR': preparation Fischer esterification RCOOH+R'OH conc H2SO4 heat reversible -> RCOOR'+H2O fruity smell. Example acetic acid + ethanol -> ethyl acetate CH3COOCH2CH3 fruity nail polish remover solvent. Hydrolysis acid or base: ester + H2O H+ or OH- -> acid+alcohol reverse saponification base gives soap RCOOR'+NaOH -> RCOONa soap + R'OH alcohol. Example fats triglyceride ester + NaOH -> glycerol + soap fatty acid Na salt.
Amide RCONH2: RCOOH+NH3 heat -> RCONH2 amide + H2O. Example acetamide CH3CONH2. Dehydration P2O5 gives nitrile RCN. Amide hydrolysis acid base gives acid back.
Uses: nylon 6,6 polyamide from adipic acid + hexamethylenediamine condensation, polyester PET from terephthalic acid + ethylene glycol, polyesters clothes bottles.
Visual Learning Method: Acid chloride SOCl2 Darzens RCOCl reactive fumes H2O acid, ester Fischer acid+alcohol H2SO4 fruity ethyl acetate hydrolysis saponification soap glycerol fats NaOH soap, amide RCOOH+NH3 acetamide nitrile P2O5, nylon 6,6 adipic hexamethylenediamine PET terephthalic ethylene glycol clothes bottles.
Daily Analogy: Derivatives like family of acid: acid chloride aggressive reactive fumes, ester fruity pleasant smell nail polish, amide stable like soap, nylon clothes made from amide linkage, polyester bottles ester linkage everyday clothes bottles.
Carboxylic Acid Derivatives
Revision Points - Easy:
- Acid chloride RCOCl RCOOH+SOCl2 Darzens best SO2+HCl gases escape very reactive hydrolyzes water back acid fumes HCl used aldehydes ketones esters amides.
- Ester RCOOR' Fischer acid+alcohol H2SO4 heat reversible fruity smell acetic+ethanol ethyl acetate nail polish remover solvent hydrolysis acid base acid+alcohol saponification base soap RCOONa+alcohol fats+NaOH glycerol+soap fatty acid Na salt soap.
- Amide RCONH2 RCOOH+NH3 heat acetamide dehydration P2O5 nitrile RCN hydrolysis acid back.
- Nylon 6,6 polyamide adipic acid+hexamethylenediamine polyester PET terephthalic acid+ethylene glycol clothes bottles.
8. Everyday Uses - Formalin Acetone Vinegar Citric Benzoic
Look around house and lab:
Formalin 40% formaldehyde HCHO aqueous solution you saw in biology lab jars preserving dead frogs fishes specimens from rotting disinfectant sterilizes equipment strong preservative handle carefully gloves pungent.
Acetone CH3COCH3 nail polish remover you saw sister using removes polish in seconds super solvent cleans glue paint grease evaporates fast flammable use ventilated area. Also solvent in paints varnishes.
Acetaldehyde CH3CHO present in ripe fruits coffee bread gives fruity aroma flavoring.
Benzaldehyde C6H5CHO almond smell used in flavoring almond essence perfumes.
Acetic acid vinegar 5% CH3COOH kitchen cooking dressings marinades pickling makes crunchy salads tasty natural cleaning grease limescale food safe adds tangy flavor. Glacial acetic acid 100% pure solidifies like ice below 16.6 C.
Citric acid from lemon sour fresh adds zing to lemonade sweets used to descale kettles remove stains natural preservative jams candies.
Benzoic acid preservative added to foods drinks juices soda packaged food prevents mold bacteria, pain reliever aspirin acetylsalicylic acid helps headaches fever reduces inflammation sore muscles also skincare gentle exfoliation.
Lactic acid CH3CH(OH)COOH sour milk muscle pain after exercise, formic acid ant sting burning.
Industrial: acetone solvent, acetic acid makes cellulose acetate photographic film, vinyl acetate for polyvinyl acetate adhesive Fevicol.
Visual Learning Method: Formalin 40% jar specimens preservative disinfectant, acetone nail polish remover super solvent glue paint grease evaporates fast flammable, acetaldehyde ripe fruits coffee bread fruity, benzaldehyde almond essence perfume, vinegar 5% acetic kitchen salad pickles cleaning grease, glacial acetic 100% ice 16.6, citric acid lemon lemonade sweets descale kettle stains, benzoic acid preservative juices soda packaged food aspirin headaches fever, lactic acid sour milk muscle pain, formic ant sting, industrial acetone solvent cellulose acetate film vinyl acetate Fevicol adhesive.
Daily Analogy: Everyday carbonyls everywhere: formalin museum preserving past, acetone eraser removes polish quickly, vinegar kitchen magic makes pickles crunchy tasty, citric lemon fresh zing, benzoic guard prevents mold bacteria like security guard in food, aspirin helper for headache fever.
Everyday Uses - Formalin Acetone Vinegar
Revision Points - Easy:
- Formalin 40% formaldehyde preservative biology specimens dead frogs disinfectant sterilizes equipment handle carefully pungent.
- Acetone nail polish remover super solvent cleans glue paint grease evaporates fast flammable solvent paints varnishes.
- Acetaldehyde ripe fruits coffee bread fruity aroma flavoring benzaldehyde almond smell almond essence perfume.
- Vinegar 5% acetic acid kitchen cooking dressings marinades pickling crunchy salads tasty natural cleaning grease limescale food safe tangy glacial acetic 100% pure solidifies ice below 16.6.
- Citric acid lemon sour fresh zing lemonade sweets descale kettles stains natural preservative jams candies.
- Benzoic acid preservative foods drinks juices soda packaged prevents mold bacteria aspirin pain reliever headaches fever inflammation skincare exfoliation.
- Lactic acid sour milk muscle pain exercise formic ant sting burning.
- Industrial acetone solvent acetic acid cellulose acetate film vinyl acetate Fevicol adhesive.
Gold Reference Table - All Formulas + Daily Life Visual - High Quality No Limit
| Concept | Formula / Easy Fact | Daily Life Visual / Uses |
|---|---|---|
| Aldehyde | R-CHO carbonyl at end one H methanal HCHO formaldehyde ethanal CH3CHO acetaldehyde benzaldehyde C6H5CHO almond | Formalin 40% preservative biology specimens pungent fruity ripe fruits almond essence |
| Ketone | R-CO-R carbonyl middle two alkyl propanone CH3COCH3 acetone butan-2-one CH3COCH2CH3 MEK acetophenone C6H5COCH3 | Nail polish remover super solvent evaporates fast glue paint grease solvent paints varnishes |
| Carboxylic | R-COOH -COOH carboxyl methanoic HCOOH formic ethanoic CH3COOH acetic benzoic C6H5COOH preservative | Vinegar 5% kitchen salad pickles sour tangy glacial 100% ice 16.6 |
| C=O polar | C delta+ O delta- electrophilic attacked by nucleophile sp2 planar 120 | Magnet C positive hungry Nu negative sticks |
| Boiling | Higher than alkanes polar dipole-dipole lower than alcohols no H-bonding between themselves propanone 56 ethanol 78 acetaldehyde 20 benzaldehyde 179 | Formaldehyde gas acetaldehyde low liquid acetone 56 benzaldehyde 179 phenyl higher |
| Solubility | Small soluble water H-bond carbonyl O accepts H from water formaldehyde fully soluble larger decreases non-polar dominates | Small soluble water larger less soluble |
| IUPAC suffix | -al methanal ethanal benzaldehyde -one propanone butan-2-one acetophenone -oic acid methanoic ethanoic benzoic | Names almond essence MEK preservative |
| Prep alcohols oxidation | Primary PCC aldehyde Jones acid over secondary ketone tertiary no oxidation | PCC stops aldehyde Jones over acid |
| Prep ozonolysis | Alkene O3 Zn H2O cleaves to carbonyls ethene 2 HCHO propene CH3CHO+HCHO | Cut double bond bridge |
| Prep alkyne hydration | H2O Hg2+ H2SO4 Markovnikov ketone ethyne acetaldehyde propyne acetone | Markovnikov ketone |
| Prep Rosenmund | RCOCl+H2 Pd BaSO4 poisoned aldehyde stops CH3COCl->CH3CHO | Half cooking stops aldehyde |
| Prep Friedel-Crafts acylation | Benzene+RCOCl AlCl3 ArCOR aryl ketone benzene+CH3COCl acetophenone | Decorating cake aromatic ketone |
| Nucleophilic addition main | C delta+ attacked Nu- tetrahedral alkoxide protonation addition product planar both sides | Magnet attack open umbrella |
| Grignard | RMgX+HCHO primary RCHO secondary R2CO tertiary new C-C bond building bigger CH3MgBr+HCHO primary ethanol? Actually formaldehyde primary acetaldehyde secondary acetone tertiary | Lego connecting blocks builds bigger alcohol |
| HCN | R2C=O+HCN R2C(OH)CN cyanohydrin CN+OH same C toxic lab only | Toxic lab only |
| NaHSO3 bisulfite | R2C=O+NaHSO3 R2C(OH)SO3Na white crystalline reversible purify separate | White precipitate test purify |
| Aldol | Alpha H dilute NaOH beta-hydroxy aldol heat dehydration alpha beta unsaturated conjugated acetaldehyde crotonaldehyde CH3CH=CHCHO acetone mesityl oxide (CH3)2C=CHCOCH3 cross aldol two different mixture | Two same friends join hands beta-hydroxy loses water conjugated stable |
| Cannizzaro | No alpha H conc NaOH disproportionation one oxidized acid salt one reduced alcohol 2HCHO CH3OH+HCOONa 2C6H5CHO C6H5CH2OH+C6H5COONa | Two no alpha H friends one gives electrons oxidized acid other reduced alcohol sharing conc NaOH |
| Haloform | CH3CO- or CH3CH(OH)- I2 NaOH CHI3 yellow ppt CH3COCH3 CHI3+CH3COONa test methyl ketones secondary alcohols ethanol positive | Yellow flag methyl ketone present ethanol positive |
| Oxidation Tollen Fehling | Aldehyde easily acid Tollen [Ag(NH3)2]+ silver mirror black Ag aldehyde yes ketone no Fehling Cu2+ blue Cu2O red ppt aliphatic aldehyde not aromatic ketone no Ketone strong oxidizer breaks C-C mixture acids | Silver mirror aldehyde polishes silver ketone cannot |
| Reduction LiAlH4 NaBH4 Wolff-Kishner Clemmensen | LiAlH4 NaBH4 aldehyde primary secondary ketone secondary H2 Ni also Wolff-Kishner NH2NH2 KOH high temp Clemmensen Zn Hg conc HCl C=O to CH2 alkane acetone to propane CH3COCH3->CH3CH2CH3 | PCC stops aldehyde Jones over acid removal O to CH2 alkane propane |
| Carboxylic prep oxidation nitrile Grignard CO2 | Primary alcohol Jones acid aldehyde oxidation Tollen Fehling Jones acid nitrile RCN hydrolysis acid base H2O H+ OH- RCOOH amide intermediate CH3CN->CH3COOH Grignard CO2 RMgX+CO2 H3O+ RCOOH builds one C more CH3MgBr+CO2 acetic acid | Over oxidation hydrolysis builds one C more |
| Carboxylic physical dimer | Dimer H-bonding 8-membered ring double H-bond higher boiling than alcohols similar mass acetic 118 ethanol 78 small soluble water H-bond larger less soluble non-polar dominates | Double handshake stronger higher boiling |
| Acidity | Stronger than phenol alcohol resonance carboxylate COO- two equivalent negative delocalized two O very stable EW NO2 Cl increase ClCH2COOH stronger than CH3COOH ED CH3 decrease order CF3COOH strongest 3F EW CCl3COOH HCOOH CH3COOH phenol weaker alcohol weaker | Two O sharing burden more stable stronger acid EW increases acidity |
| Reactions NaHCO3 esterification decarboxylation Kolbe | NaHCO3 CO2 bubbles effervescence test RCOOH+NaHCO3 COONa+H2O+CO2 distinguishes phenol no bubbles NaOH salt COONa+H2O Esterification RCOOH+R'OH conc H2SO4 heat RCOOR'+H2O Fischer fruity acetic+ethanol ethyl acetate fruity nail polish remover also Decarboxylation RCOONa+NaOH CaO heat RH+Na2CO3 removes CO2 Kolbe electrolysis RCOONa electrolysis R-R higher alkane | CO2 bubbles test esterification marriage fruity child water decarboxylation removes CO2 |
| Derivatives acid chloride ester amide | Acid chloride RCOCl RCOOH+SOCl2 RCOCl+SO2+HCl gases escape Darzens best pure RCOOH+PCl5 RCOCl+POCl3+HCl very reactive hydrolyzes water RCOCl+H2O RCOOH+HCl fumes used aldehydes ketones esters amides Ester RCOOR' Fischer RCOOH+R'OH conc H2SO4 heat reversible RCOOR'+H2O fruity acetic+ethanol ethyl acetate nail polish remover solvent hydrolysis acid base acid+alcohol saponification base soap RCOOR'+NaOH RCOONa soap+R'OH alcohol fats triglyceride ester+NaOH glycerol+soap fatty acid Na salt Amide RCONH2 RCOOH+NH3 heat RCONH2+H2O acetamide dehydration P2O5 nitrile RCN hydrolysis acid back Uses nylon 6,6 polyamide adipic+hexamethylenediamine polyester PET terephthalic+ethylene glycol clothes bottles | Acid chloride aggressive fumes ester fruity nail polish saponification soap glycerol fats NaOH soap amide stable nylon clothes PET bottles |
| Everyday formalin | 40% HCHO aqueous preservative biology specimens dead frogs fishes rotting disinfectant sterilizes equipment strong preservative handle carefully gloves pungent | Biology lab jars dead frogs |
| Acetone | CH3COCH3 nail polish remover super solvent cleans glue paint grease evaporates fast flammable ventilated solvent paints varnishes | Sister removes polish seconds super solvent |
| Acetaldehyde benzaldehyde | CH3CHO ripe fruits coffee bread fruity aroma flavoring C6H5CHO almond smell almond essence perfumes | Fruity aroma coffee bread almond essence perfume |
| Vinegar acetic | 5% CH3COOH kitchen cooking dressings marinades pickling crunchy salads tasty natural cleaning grease limescale food safe tangy glacial 100% pure solidifies ice below 16.6 | Kitchen salad pickles cleaning grease tangy ice solidifies 16.6 |
| Citric benzoic lactic formic | Citric lemon sour fresh zing lemonade sweets descale kettles stains natural preservative jams candies Benzoic preservative foods drinks juices soda packaged prevents mold bacteria aspirin pain reliever headaches fever inflammation skincare exfoliation Lactic sour milk muscle pain exercise Formic ant sting burning | Lemon zing lemonade sweets descale benzoic guard prevents mold aspirin helper headache sour milk muscle pain ant sting burning |
| Industrial | Acetone solvent acetic acid cellulose acetate photographic film vinyl acetate polyvinyl acetate adhesive Fevicol | Solvent film adhesive Fevicol |
Final Exam Ready Revision - Easy Day-to-Day Hooks - No Limit Detailed: