ORGANIC REACTIONS

Tests to identify the carbonyl compounds

-2,4 DNPH: colourless to reddish orange -Tollens Reagent test Reagent: AgNO3 in aq.NH3 (produces Ag+ ions acting as mild oxidising agent) Condition: Warm Colour change: Colourless to silver mirror -Fehlings test Reagent: Cu2+/ alkali (acts as mild oxiding agent) Condition: Warm Colour change: Blue to brown -Iodoform test Reagent: I2/NaOH Condition: Warm Colour change: Colourless to yellow ppt.

Preparation of aldehydes

-Partial oxidation of primary alcohol -Partial oxidation of alkene

Preparation of Ketone

-Partial oxidation of seconday alcohol -Partial oxidation of alkene

Substitution by CN-

Reagent: KCN in ethanol Condition: Reflux CN substitutes Cl to produce Cl- ion

Reduction of Carboxylic acids

Reagent: LiAlH4/ dry ether: acts as solvent for LiAlH4 Condition: Warm Carboxylic acid ---> Alcohol + H2O 2H is added to C and 2H is added to oxygen that's double bonded to C to form H2O

Substitution by NH3 in ethanol

Reagent: NH3 in ethanol Condition: Reflux Cl forms bond with H from NH3 to form H-Cl and NH2 takes place of Cl

Displacement of Alcohols

Reagent: Na Condition: Heat CH3CH2OH + Na --> CH3CH2ONa + 1/2H2

Reduction of Ketones

Reagent: NaBH4/Alkali Condition: Warm H is added to O double bonded to C and H is added to C involved in double bonding Alcohol formed

Reduction of Aldehydes

Reagent: NaBH4/Alkali Condition: Warmed H is added to O doubled bonded to C and H is added to C involved in double bonding Alcohol formed

Substitution by aqueous NaOH

Reagent: NaOH (aq) or KOH Condition: Reflux OH substitutes Cl to produce Cl- ion

Elimination reaction

Reagent: NaOH in ethanol Condition: Reflux HBr is removed to give NaBr and H2O

Hydrolysis of nitrile

Reagent: NaOH/ H2O Condition: Reflux CH3CH2CN ---> CH3CH2COONa + NH3 + H2O

Alkaline hydrolysis

Reagent: NaOH/H2O Condition: Reflux

Substitution by PCl3

Reagent: PCl3 Condition: Reflux 3CH3OH + PCl3 --> 3CH3Cl + 3H3PO3

Substitution by PCl5

Reagent: PCl5 Condition: Room temp. CH3CH2CH2OH + PCl5 --> CH3CH2CH2Cl + POCl3 + HCl

Substitution by SOCl2

Reagent: SOCl2 Condition: Reflux CH3CH2CH2OH + SOCl2 --> CH3CH2CH2Cl + SO2 + HCL

Substitution by X-

Reagent: X-/ aqueous Condition: Reflux Cl- > Br- > I- > CH3CH2Cl + Br- --> No reaction CH3CH2Br + Cl- --> CH3CH2Cl + Br-

Polymerisation reaction

Reagent: alkene Condition: High temp. and pressure Molecular formula remains the same Branch the methyl group Continuation shown by extended line at the ends

Substitution by dry HCl

Reagent: dry HCl Condition: Reflux C2H5OH + HCl --> C2H5Cl + H2O

Mechanism Of Nucleophilic Substitution

SN1: Substitution by a nucleophile where rate would be dependent upon 1 factor Tertiary halogenoalkane SN2: Substitution by a nucleophile where rate is dependent upon 2 factors Primary halogenoalkane

Preparation of Alcohol

SN2: Halogenoalkane reacts with aqueous NaOH to give alcohol and NaCl Electrophilic Addition: Alkene reacts with steam to give an alcohol

Alkanes

Saturated hydrocarbon Reactions: Complete combustion Incomplete combustion Free Radical Substitution

Oxidation of Aldehyde

gives carboxylic acid

Hydrolysis of esters

Acid hydrolysis Alkaline hydrolysis

Converting CH3CH2COONa to CH3CH2COOH

Acidification Reagent: H2O/H+ Condition: Reflux

Combustion of alcohols

Alcohol + oxygen --> carbon dioxide + water

Electrophilic addition mechanism

Br2 molecule becomes instantaneous dipole Double bond being nucleophile attracts Br+ and forms carbocation [slow step] Carbocation is organic intermediate Carbocation reacts with Br- [fast step]

Incomplete Combustion of Alkanes

CO, C, NOx + CxHy NOx: Engines run at a high temp. so nitrogen and oxygen in the air react Can lead to acid rain CO: Carboxyhaemoglobin; death C: Respiratory problems CxHy: Fuel effiency decreases

Catalytic Converter

Catalyst: Platinum/ Rhodium Redox reaction: CO + NOx--> CO2 + N2 CxHy --> CO2 + H2O

Initiation

Chlorine splits by homolytic fission in the presence of sunlight to produce 2 chlorine free radicals

Displacement of Carboxylic acids

Condition: Reflux CH3COOH + Na ---> CH3COONa + H2

Neutralization of Carboxylic acids

Condition: Reflux CH3COOH + NaOH --> CH3COONa + H2O CH3COOH + Na2CO3 --> 2CH3COONa + CO2 + H2O CH3COOH + NaHCO3 --> CH3COONa + H2O + CO2

Reaction of Carboxylic Acids

Displacement Neutralization Reduction

Production of alcohol

Fermentation: Anaerobic respiration of yeast at 37°C

Reduction of aldehyde & ketone

Gives alcohol

Oxidation of Ketones

No reaction

Oxidation of tertiary alcohol

No reaction

Halogenoalkanes

Obtained from free radical substitution Nucleophilic substitution reaction Elimination reaction

Propagation

One reactant is a radical and one product is a radical First step: The chlorine radical removes H from methane to produce hydrogen chloride and methyl radical Second step: The methyl radical reacts with Cl2 to produce CH3Cl and chlorine radical

Addition of halogens

Reagent: Br2/ H2O Condition: Room temp. Br is added to every carbon involved in double bonding

Free radical substitution

Reagent: Cl2 Solvent: H2O Condition: Sunlight Initiation Propagation Termination

Mild oxidation of alkenes

Reagent: Cold Diluted KMnO4/ H+ Condition: Room temp. OH is added to every carbon atom involved in double bonding Double bond broken to single bond

Dehydration of alcohols

Reagent: Conc. sulphuric acid/ Al2O3/ Pumice stone Condition: Heat CH3CH2OH --> CH2=CH2 + H2O H and OH is removed

Esterification

Reagent: Concentrated H2SO4 Condition: Reflux Carboxylic acid + Alcohol --> Ester + H2O OH from alcohol and H from carboxylic acid is removed to form water Forward reaction: conc. H2SO4 Reverse reaction: dilute H2SO4

Addition of hydrogen

Reagent: H2/ Nickel Condition: 140°c H is added to every carbon involved in double bonding

Acid hydrolysis

Reagent: H2O/ H+ Condition: Reflux Ester hydrolysed to carboxylic acid and alcohol

Addition of steam

Reagent: H2O/ conc. H3PO4 Condition: 330°c , 6Mpa H and OH is added Isomerism exists Alcohol with most alkyl groups is stable hence more percentage formed

Acidification

Reagent: H2O/HCl Condition: Reflux CH3COONa ----> CH3COOH + NaCl

Hydrolysis of nitrile

Reagent: H2O/HCl Condition: Reflux Cyanide --> Carboxylic acid + NH4Cl N, 2H2O and Cl form NH4Cl

Nucleophilic addition reaction

Reagent: HCN/NaCN (catalyst) Condition: Reflux H is added to O doubled bonded to C and CN is added to C involved in double bonding

Partial oxidation of alkene

Reagent: Hot conc. kMnO4/H+ Condition: Distill Oxygen is added to a carbon CO2 produced if CH2 present at the double bond H2O produced

Strong oxidation of alkenes

Reagent: Hot, conc. KMnO4/ H+ Condition: Reflux =CH2 --> CO2 + H2O =CH --> -COOH =C --> C=O

Partial oxidation of alkene

Reagent: Hot.conc. kMnO4/H+ Condition: Distill An oxygen is added to carbon atom If CH2 is present at double bond, CO2 is produced H2O is produced

Addition of Hx

Reagent: Hx Condition: Room temp. H and Cl is added Isomerism exists

Oxidation of alcohols

Reagent: K2Cr2O7/ H+ OR hot conc. KMnO4/H+ Condition: Reflux H2O produced as product Primary alcohol oxidized to carboxylic acid Secondary alcohol oxidized to ketone Tertiary alcohol --> no reaction

Partial oxidation of primary alcohol

Reagent: K2Cr2O7/H+ Condition: Distill Oxygen atom removes two H to form water & aldehyde

Oxidation of Aldehydes

Reagent: K2Cr2O7/H+ Condition: Reflux An oxygen is added to H to form carboxylic acid

Partial oxidation of secondary alcohol

Reagent: K2Cr2O7/H+ Condition: Reflux Oxygen atom removes 2H to form H2O and ketone

Nucleophilic Substitution reaction

Substitution by aqueous NaOH Substitution by KCN Substitution by NH3 Substitution by X-

Nucleophilic Substitution reaction

Substitution by dry HCl Substitution by SOCl2 Substitution by PCl5 Substitution by PCl3

Test for ketone

Tollens Reagent test: no reaction Fehling's test: no reaction

Termination

Two radicals join to form a molecule 2 chlorine radicals react to form chlorine 2 methyl radicals react to form ethane 1 methyl radical reacts with 1 chlorine radical to form CH3Cl

Alkenes

Unsaturated hydrocarbon Obtained from cracking of higher alkanes Any reaction over double bond is electrophilic addition reaction

Complete Combustion of Alkanes

alkane + oxygen -> carbon dioxide + water The number of CO2 is the same as the number of carbons in the alkane The number of H2o is half the number of hydrogen General Formula : CxHy + (x+y/4)O2-> xCO2 + y/2H2o