ORGANIC COMPOUNDS CONTAINING OXYGEN
- Created by: Katy **
- Created on: 10-04-16 14:38
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- ORGANIC COMPOUNDS CONTAINING OXYGEN
- FORMING PRIMARY & SECONDARY ALCOHOLS
- nucleophilic substitution of haloalkane
- reflux NaOH aq
- form alcohol & NaX
- halogens bonded directly to benzene cannot act readily
- reduction of aldehydes & ketones
- sodium tetrahydrioborate (III) dissolved in water (NaBH4)
- lithium tetrahydrioaluminate (III) in dry ether + dilute HCl (LiAlH4)
- addition reaction of industrial from alkenes
- steam, 600atm, 300'C
- catalyst is conc. phosphoric acid
- no co-procudts, HIGHER yield
- alcohol properties
- HIGH boiling point due to hydrogen bonds
- soluble in water as polarised & hydrogen bonding with water
- volatile due to hydrogen bonds with each other
- biofuel as it is a renewable resource
- alcohol + HX will form haloalkane + water by nucleophilic substitution
- nucleophilic substitution of haloalkane
- PRODUCTION OF ESTERS & ALKENES FROM ALCOHOLS
- ester = sweet smelling liquids
- alcohol + acid chloride @ room temp.
- forms ester + HCl(g)
- HCl(g) is an irritant so should be in fume cupboard
- HIGH ester yield, no catalyst or reflux
- forms ester + HCl(g)
- excess alcohol + carboxylic acid @ REFLUX
- catalyst conc. sulfuric acid
- remaining acid neutralised be NaHCO3
- forms ester + water
- water is the only bi-product
- limited ester yield, reversible reaction, catalysts is toxic
- dehydration of alcolhols
- forms alkene
- remove water by WARMING & vapour passed over aluminium oxide or excess conc. sulfuric acid
- OXIDATION OF PRIMARY & SECONDARY ALCOHOLS
- oxidising agent is acidified potassium dichromate in sulphuric acid
- primary alcohol to aldehyde to carboxylic acid
- distil for aldehyde
- reflux for carboxylic acid
- secondary alcohol to ketone + REFLUX
- REACTIONS OF PHENOL
- phenoxide ion
- presence of benzene ring weakens -OH bond
- phenols are acidic in (aq) solutions
- very stable as negative charge is spread around the ring
- test for phenol
- neutral iron(III) chloride
- yellow to purple
- phenol + acid chloride forms an ester
- phenol + bromine water forms 2,4,6-triobromophenol (white ppt.)
- electrophilic substitution
- -OH bonded directly to benzene ring increases electron density & more reactive than benzene
- electrophilic substitution
- soluble in water due to hydrogen bonds
- nucleophilic substitution of phenol + HBr will decolourise the water + form a white ppt. with an antiseptic smell
- phenoxide ion
- IDENTIFYING ALDEHYDES & KETONES
- carbonyl compounds(C=O)
- Tollen's Reagent (AgNO3, NH3, NOH) WARM
- aldehyde forms a "silver mirror"
- ketone
- Fehling's Reagent (CuSO4, NaK titrate, NaOH) WARM
- aldehyde turns blue to brick red
- ketone
- nucleophilic substitution-elimination reaction of 2,4-dinitrophenylhydrazine (2,4-DNHP)
- aldehyde & ketone form a crystalline orange-yellow ppt. that is filters & purified
- compare with book melting point values
- aldehyde & ketone form a crystalline orange-yellow ppt. that is filters & purified
- Iodoform Test (I2, NaOH)
- CH3C=O & CH3CH(OH) forms a pale yellow ppt.
- ADDITION OF HYDROGEN CYANIDE TO CARBONYL COMPOUNDS
- HCN is toxic so made in situ (sulfuric acid + KCN)
- increases the carbon chain
- nucleophilic addition
- PHYSICAL PROPERTIES OF CARBOXYLIC ACIDS
- lower members are colourless liquids with a "sharp" smell
- boiling point increases with chain length as increase in Van der Waals forces, increasing energy needed to overcome bonds
- soluble in water as can hydrogen bond
- longer chain, more non-polar & not bond so become insoluble
- ACIDITIES OF CARBOXYLIC ACIDS, PHENOL, ALCOHOLS & WATER
- water < alcohol < phenol < carboxylic acid
- carboxylic acid forms R-COO- & H3O+ ion
- FORMING CARBOXYLIC ACIDS BY OXIDATION
- oxidation of primary alcohols
- acidified potassium dichromate, conc. sulphuric acid, dilute HCl, REFLUX
- oxidation of alkylbenzene
- alkaine potassium maganate(VII) solution, HCl, REFLUX
- reduction of carboxylic acids
- Lithium tetrahydridoaluminate(III), LiAlH4 to alcohol
- decarboxylation = reduce carbon chain length
- add sodalime (NaOH, Ca(OH)2), HEAT
- oxidation of primary alcohols
- FORMING ACID CHLORIDES FROM CARBOXYLIC ACIDS & THEIR REACTIONS
- making acid chloride
- add phosphorus(V) chloride, PCl5
- forms acid chloride, POCl3, HCl
- add phosphorus(V) chloride, PCl5
- reactions of acid chlorides
- acid chloride + alcohol forms esters + HCl
- acid chloride + water forms carboxylic acid
- acid chloride + carboxylic salt forms acid anydride
- not violently reactive, ethanoic anhydride forms asprin
- making acid chloride
- FORMING PRIMARY & SECONDARY ALCOHOLS
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