Summary of Organic reactions

A summary of organic reactions used in Salters A2/AS chemistry

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  • Created by: Charlie
  • Created on: 06-05-10 19:29

Chemical Tests

Alcohol or Aldehyde: Add acidified potassium dichromate K2CrO7

Colour change Orange ---> Green

Halide ions: Add Silver nitrate AgNO3 + HNO3

Forms a precipitate AgX

Amines:Smells like putrefying flesh, pH >7 in aqueous conditions

Phenols: Add neutral Iron (III) chloride

Colour change from orange ----> purple

Acid: Add Na2CaCO3, pH<7 and CO2 gas given off

Unsaturation: Add Bromine water Br2(aq)

Colour change from brown to colourless

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Alkanes

Alkanes: Fully saturated hydrocarbons eg. Hexane

Reactions:

1.Combustion in oxygen. eg CH4+2O2 --> CO2 +H2O

2.Free radical substiution

Breakdown in the presence of UV.

a) Initiation

b) propogation

c) Termination

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Alkenes

Alkenes: functional group containing a double bond between two carbons C=C.

Reactions:

1. Electrophilic addition.

2. Addition polymerisation.

3.Free radical substitution.

(-CH=CH-) ---H2(g), finely divided Ni at 150c and 5atm--> (-CH2-CH2-)

(-CH=CH-) ---Br2, room temp organic solvent---> (-CHBr-CHBr-)

(-CH=CH-) ---Conc HBr, room temp ---> (-CH2-CHBr-)

(-CH=CH-) ---Trace O2(g) 200c and 1500atm --->(-CHR-CHR'-) addition polymer

(-CH=CH-) ---H2O(g), phosphoric acid catalyst, 300c, 60atm ---> (-CH2-CH(OH)-)

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Alcohols

Alcohols: A carbon attached to an -OH group which is not a delocalised system.

Reactions:

1.Dehydration:(Elimination) loss of a small molecule.

2.Oxidation.(primary--->aldehyde, Secondary-->ketone)

3.Nucleophilic substiution.

4.Esterification.

R-CH2OH ---R'-COClor (R'CO)2O, anhydrous conditions ---> (R-CH2-O-CO-R')

R-CH2OH ---AlO3(s), 300c or C.H2SO4 reflux--->(R-CH2=CH2-R')

R-CH2OH(primary) ---Cr2O7 2-,distil-->R-CHO---Cr2O7 2-, Reflux--->R-COOH

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Halogenoalkane

Halagenoalkane: An alkane attached to either F, Cl, Br or I (X)

R--X --------c.NH3--Heat in a sealed tube---> R-NH3

Amine

R--X --------H2O--(slow)---> R-OH

Alcohol

R--X -----NaOH--Reflux---> R-OH

alcohol

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Aldehydes and Ketones

Aldehyde: R-CO-H

R-CO-H ---NaBH4---> R-CH2-/primary alcohol

R-CO-H ---CrO7 2-/H+, reflux---or Heat with Fehling's solution--->R-CO-OH carboxylic acid

R-CO-H ---HCN (+alkali)-----> HO-RCH-CN a cyanohydrin

Ketone: R-CO-R'

R-CO-R' ---NaBH4----> R-CH(OH)-R' secondary alcohol

R-CO-R' ---HCN (+alkali)---> HO-RCH-CN a cyanohydrin

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Carboxylic Acids

Carboxylic Acid: R-CO-OH

R-CO-OH ---NaOH---> R-CO-O-

R-CO-OH ---reflux with aqueous(H+/OH-)---> R-CO-O-R'

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Arenes

An Arene is a ring containing 6 carbons, 6 hydrogens and a delocalised ring of electrons

C6H6 --- Br(aq), FeBr3, room temperature---> C6H5Br

C6H6 --- H2, finely divided Ni, 300c, 30atm ---> C6H12

C6H6 --- AlCl3(anhydrous), reflux, R-COCl or (RCO)2O---> C6H5-CO-R

C6H6 --- AlCl3(anhydrous), reflux, R-Cl ---> C6H5-R

C6H6 --- c.HNO3, c.H2SO4, <55c ---> C6H5-NO2

C6H6 --- AlCl3, room temp, Cl(g) ---> C6H5-Cl

C6H6 --- c.H2SO4, reflux --->C6H5-SO2OH

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Comments

Dave

Not bad, could be clearer though? Still, 4 stars, thank you :)

fmPerkins

The layout makes it a little bit of a challenge to read it... But thank you :)

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