Turn on thread page Beta
    • Thread Starter
    Offline

    1
    ReputationRep:
    um. i dunno if these are right - anyone tell me if i missed anything?

    Diazotisation

    amine + nitrous acid with dilute HCl/H2SO4 to form diazonium salt. keep below 10°.
    react diazonium salt with phenol in excess alkali.

    Electrophilic Substitution

    nitric acid + sulphuric acid -> H2O + H2SO3- + NO2+
    NO2+ + benzene --> nitrobenzene + sulphuric acid
    60°

    Electrophilic Addition

    phenol + 3Br2 --> 2,4,6 tribromophenol + 3HBr
    halogen carrier catalyst

    Chain Extension

    add KCN
    KCN + H+ --> HCN + K+
    add above to molecule to be extended
    acid hydrolysis of product to remove N and add hydrogens...
    • Thread Starter
    Offline

    1
    ReputationRep:
    Ester Chemistry

    Alcohol + Carboxylic Acid <=> Ester

    forward is acid catalyst, H2SO4, reflux
    reverse is alkali catalyst, NaOH, reflux

    Alcohol, Aldehyde, Ketone, Carboxylic Acid

    Alcohol Test = react with phosphorus chloride to produce whitey mist
    Carbonyl Test = Adding2,4 DNPH gives yellowy colour
    Aldehyde/Ketone test = Add Tollen's Reagent, silver mirror => aldehyde

    primary alcohol + K2Cr2O7/H2SO4 ==heat=> aldehyde (orange to green)
    primary alcohol + K2Cr2O7/H2SO4 ==reflux=> carboxylic acid (orange to green)

    secondary alcohol + K2Cr2O7/H2SO4 ==reflux=> ketone (orange to green)
    tertiary alcohol + K2Cr2O7/H2SO4 ==reflux=> tertiary alcohol (orange to orange)
    • Community Assistant
    • Study Helper
    Online

    17
    ReputationRep:
    Community Assistant
    Study Helper
    (Original post by El Chueco)
    um. i dunno if these are right - anyone tell me if i missed anything?

    Diazotisation

    amine + nitrous acid with dilute HCl/H2SO4 to form diazonium salt. keep below 10°.
    react diazonium salt with phenol in excess alkali.

    Electrophilic Substitution

    nitric acid + sulphuric acid -> H2O + H2SO3- + NO2+
    NO2+ + benzene --> nitrobenzene + sulphuric acid
    60°

    Electrophilic Addition

    phenol + 3Br2 --> 2,4,6 tribromophenol + 3HBr
    halogen carrier catalyst

    Chain Extension

    add KCN
    KCN + H+ --> HCN + K+
    add above to molecule to be extended
    acid hydrolysis of product to remove N and add hydrogens...
    only aromatic amines form diazonium salts
    aliphatic compounds decompose spontaneously

    Br2 does not need a halogen carrier catalyst with phenol (nor phenylamine)
    halogen carriers are needed to add to non-activated rings eg benzene
    • Thread Starter
    Offline

    1
    ReputationRep:
    Addition Polymerisation

    monomer, 60°C, low pressure, Zeigler-Natta catalyst => polymer

    Isotactic = branches on alternating sides => high mpt because of strong vdw
    Syndiotactic = branches on same side => middle mpt because significant vdw
    Atactic = no order to branching => low mpt because low vdw forces.

    Condensation Polymerisation

    joining of two molecules with exclusion of water

    diol + dicarbo acid - nylon-6,6
    dipeptides
    polyesters

    Acid Hydrolysis makes
    Alkaline Hydrolysis breaks
    Offline

    13
    ReputationRep:
    What do you mean by "acid hydrolysis makes" and "alkaline hydrolysis breaks"?
    • Thread Starter
    Offline

    1
    ReputationRep:
    (Original post by endeavour)
    What do you mean by "acid hydrolysis makes" and "alkaline hydrolysis breaks"?
    good question. i presume acid hydrolysis joins the monomers, and alkaline hydrolysis splits the polymer...
    Offline

    1
    ReputationRep:
    you forgot that ketones/aldehydes can be turned back into primary and secondary alcohols using NaBH4
    Offline

    13
    ReputationRep:
    (Original post by El Chueco)
    good question. i presume acid hydrolysis joins the monomers, and alkaline hydrolysis splits the polymer...
    "Hydrolysis" is the addition of water, which would always break the ester bond.
    You can hydrolyse an ester (break the ester bond) with an alkali (and reflux), which would produce its consituent alcohol, but also a salt (instead of carboxylic acid, which you'd get with acid hydrolysis).
    Eg CH3COOCH2CH3 + NaOH -> CH3COO-Na+ + CH3CH2OH.
    Offline

    4
    ReputationRep:
    Conc HNO3/H2S04 in electrophilic subst! they mark down for no 'conc'
    Offline

    1
    ReputationRep:
    and you missed out halogenation and alkylation of benzene- alkylation happens at 60degrees and both need a halogen carried, like AlCl3. halogenation requires just a halogen, alkylation requires a helogenoalkane
    • Thread Starter
    Offline

    1
    ReputationRep:
    (Original post by CogitoErgoSum)
    and you missed out halogenation and alkylation of benzene- alkylation happens at 60degrees and both need a halogen carried, like AlCl3. halogenation requires just a halogen, alkylation requires a helogenoalkane
    hehe. i cant be expected to remember it all from january, especially as that exam didnt go so well then and i've had no notes since...
    Offline

    0
    ReputationRep:
    (Original post by CogitoErgoSum)
    and you missed out halogenation and alkylation of benzene- alkylation happens at 60degrees and both need a halogen carried, like AlCl3. halogenation requires just a halogen, alkylation requires a helogenoalkane
    ?
    ??
    Offline

    1
    ReputationRep:
    (Original post by El Chueco)
    Electrophilic Addition

    phenol + 3Br2 --> 2,4,6 tribromophenol + 3HBr
    halogen carrier catalyst
    This is electrophilic substitution, not addition.
 
 
 
Turn on thread page Beta
Updated: June 22, 2005
The home of Results and Clearing

3,015

people online now

1,567,000

students helped last year

University open days

  1. Sheffield Hallam University
    City Campus Undergraduate
    Tue, 21 Aug '18
  2. Bournemouth University
    Clearing Open Day Undergraduate
    Wed, 22 Aug '18
  3. University of Buckingham
    Postgraduate Open Evening Postgraduate
    Thu, 23 Aug '18
Poll
How are you feeling about GCSE results day?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.