Doc Brown's Chemistry Clinic

 GCE-AS-A2-IB ADVANCED LEVEL ORGANIC CHEMISTRY

 A summary of organic REACTION MECHANISMS

INTRODUCTION page with links to detailed Parts Ia-IV revision-information notes

Revision notes include full diagrams and explanation of the mechanisms and the 'molecular' equation and reaction conditions and other con-current reaction pathways and products are also explained. PLEASE ALLOW TIME for the many graphic images-pictures-diagrams to download!!! © Dr W P Brown

Alphabetical list of organic terminology * EMAIL query?comments

PLEASE NOTE:

1. Whatever their abstract nature (and 'truthfulness'!) a study of mechanisms is important to understand how organic chemical reactions take place and why molecules react in a particular way. It also allows predictions of what might happen to an organic molecule with a particular reagent. They also explains why, in many cases, there is more than one organic product of the reaction or an unexpected product is formed.

2. I thank Jim Clark at http://www.chemguide.co.uk for his patience, advice and email discussions of issues involved in the representation of organic reaction mechanisms. 

3. Many of the graphic images are quite compressed in design. This is quite deliberate, so that they will fit on screen plus text lines in future quizzes.

4. The image numbers 1, 2, 3 etc. are NOT meant to be sequential, its just the order they were drawn!

5. Unless otherwise stated R or R' = H, alkyl (e.g. -CH₂CH₃) or aryl (e.g. C₆H₅),

   • and for simplicity, R₂ or R₃ does not imply that the 2 or 3 R's have to be the same.

PLEASE ALLOW TIME for the many © Dr W P Brown graphic images-pictures-diagrams to download!!!

Main molecule index - each page has a mechanism sub-index

Part Ia Alkane mechanisms * Part Ib Alkene mechanisms

• abstraction: When one reacting species removes an atom/ion from another molecule, radical or ion.

  • e.g. a methyl radical abstracts a chlorine atom from a chlorine molecule

    • CH₃^. + Cl₂ ==> CH₃Cl + ^.Cl  (see mechanisms Part Ia)

  • or a water molecule abstracting a proton from a protonated alcohol molecule

    • H₂O + CH₃CH₂OH₂⁺ ==> H₃O⁺ + CH₃CH₂OH  (see mechanisms Part III)

    • Though the phrase proton transfer is more appropriate here.

• acylation: The introduction of a R-C=O group into a molecule (R = alkyl or aryl).   (see mechanisms Part IV)

• acylonium ion: A type of carbocation formed in the electrophilic substitution alkylation of aromatic compounds

  • e.g. CH₃-C⁺=O or CH₃CO⁺  where the positive charge is carried on the carbon of the C=O bond. They are formed e.g. in the aluminium chloride catalysed acylation of aromatic compounds.   (see mechanisms Part IV)

• activated complex: An unstable or 'transient state' formed when two reactant particles collide with sufficient kinetic energy in a reaction mechanism step. The activated complex breaks down to give the products.   (see mechanisms Part II)

• activation energy E_a: The minimum energy reacting particles must possess in order to form an 'activated complex' or transition state before forming the products. Its the top of the hump on a reaction progress energy profile diagram.   (see mechanisms Part II)

• addition: The adding of one molecule to another with no other product, but not necessarily in a single reaction step.

  • The molecule is often added in two parts across e.g. a double bond

    • e.g. electrophilic addition of hydrogen halide to alkenes:

      • >C=C< + HX ==> >CH-CX<   (see mechanisms Part Ib)

    • or nucleophilic addition of hydrogen cyanide to aldehydes/ketones

      • >C=O + HCN ==> >C(OH)-CN   (see mechanisms Part III)

• alkoxy group: An alkyl-oxygen part of a molecule e.g. CH₃CH₂-O- is an ethoxy group.

• alkyl group: A saturated section of a molecule derived from an alkane e.g.

  • -CH₃ methyl, -CH₂CH₃ ethyl, or -CH₂CH₂CH₃ propyl etc.

• arrows, use of in mechanisms: A half-arrow head means a single electron shift and a full arrow head shows an electron pair shift and used in the context of making or breaking bonds. Examples: 1. to 2. show single electron shifts and 4. to 6. show bond pair shifts.

  1. The bonding pair of electrons of the chlorine molecule is split between the two chlorine atoms/radicals on homolytic bond fission in the initiation of a free radical chain reaction.   (for 1. and 2. see mechanisms Part Ia)

      

  2. One electron from each radical pairs up to form a C-Cl covalent bond in a free radical chain termination step.

      

  3. A bond pair from the alkene is donated to a proton on the oxonium ion, H₃O⁺, forming a C-H bond and simultaneously the H-O bond pair moves completely on to the oxygen to form a lone pair of non-bonding electrons.   (see mechanisms Part Ib)

      

  4. A hydroxide ion, OH^-, donates a lone pair of non-bonding electrons to a carbon atom to form a C-OH bond and simultaneously the C-Cl bond pair shifts to become a lone pair of electrons on the chlorine atom as a chloride ion is formed.   (see mechanisms Part II)

      

  5. The cyanide ion, ^-CN, donates a lone pair of electrons to form a C-N bond and simultaneously one of the C=O bond pairs moves completely on to the oxygen to form a lone pair of non-bonding electrons and giving the oxygen atom an overall single positive charge.   (see mechanisms Part III)

      

  6. The C-H bond pair shifts to complete the ∏ electrons of the benzene ring and simultaneously a hydrogensulphate ion donates a lone pair and forms an H-O bond in forming a sulphuric acid molecule.    (see mechanisms Part IV)

      

• 

  aryl group: A section of a molecule derived from aromatic compounds like benzene or methylbenzene

  • e.g. the phenyl group is the simplest, C₆H₅- or

• attacking ... : A somewhat dramatic term applied to the 'active' part of a reagent that directly interacts with the organic 'substrate' molecule in question. You can use phrases like 'nucleophilic attack' or 'electrophilic attack'.

  • e.g. the nucleophile OH^- 'attacking' the positive carbon of the polarised C^δ+-Cl^δ- bond in a nucleophilic substitution of halogenoalkane

  • or the positive part of the polarised H^δ+-Br^δ- electrophile attacking the ∏ electrons of an alkene double bond in an electrophilic addition reaction.

• 'bimolecular' mechanism/kinetics : see e.g. S_N2

• bond fission: This means breaking a bond between two atoms to give two 'fragments' (atoms, ions or molecules), but there are two modes of fission, depending on what happens to the original bonding pair of electrons. This is illustrated by the breaking of a C-Br (or C:Br) bond.

  • Heterolytic bond fission: The bonding pair of electrons (: below) leaves with one of the fragments and usually leads to ion formation. This follows from the bond polarity,  C^δ+-Cl^δ- due the difference in electronegativity (Cl > C).

    • e.g. (CH₃)₃C:Cl ==> (CH₃)₃C⁺ + :Cl^-    (see mechanisms Part II)

    • 

  • Homolytic bond fission: The bonding pair of electrons is 'split' between the two fragments with an unpaired electron and usually leads to the formation of free radicals initiated by heat or uv light.

    • e.g. H₃C:Cl ==> H₃C^. + Cl^.    (see mechanisms Part Ia)

      

       

• bromonium ion:  A form of carbocation produced in the 1st step of the electrophilic addition of bromine to an alkene. It involves a C-Br-C bonded triangle which carries the positive charge. The addition of chlorine proceeds in the same way via a chloronium ion.   (see mechanisms Part Ib)

• carbocation (carbonium ion): A positive ion derived from an organic molecule where the charge is usually carried by a carbon atom e.g. the ethyl carbocation is CH₃CH₂⁺ , and note that the three bonds from the carbon carrying the positive charge are in a trigonal planar configuration (2 x C-H and a C-C in this case).   (see mechanisms Part Ib)

• chain reaction : Here the term is often used in the context of highly reactive free radicals, where in a reaction step, one radical brings about a chemical change and forms another reactive radical to continue the reaction.   (see mechanisms Part Ia)

  • e.g. a chain propagation step in uv/Cl₂ chlorination of alkanes

    • CH₃^. + Cl₂ ==> CH₃Cl + ^.Cl

      • where the chlorine radical ^.Cl can continue the reaction.

• E1: Shorthand for an elimination reaction in which the rate determining step involves just one of the reactant molecule or intermediate (X) and the rate is independent any other reactant or intermediate.   (see mechanisms Part II)

  • This results in overall 1st order reaction kinetics: e.g. rate = k₂[X]

• E2: Shorthand for a nucleophilic substitution reaction in which the rate determining step is a bimolecular collision of two reactant molecules or intermediates (X and Y) and the rate is independent any other reactant or intermediate.   (see mechanisms Part II)

  • This results in overall 2nd order reaction kinetics: e.g. rate = k₂[X][Y]

• electron shift: see use of arrows in mechanisms

• electronegativity: The electron attracting power of an atom in a covalent bond situation.

  • One of the most common scales used is the Pauling electronegativity and a selection of values is listed.

  • e.g. Na 0.9, Al 1.5, C 2.1, H 2.1, P 2.1, S 2.5, Br 2.8, Cl 3.0, N 3.0, O 3.5, F 4.0

  • The concept is important when considering polar bonds, which arise when there is a significant electronegativity difference between two atoms in a bond. The bigger the difference, the more polar the bond. Polar bonds can determine how a molecule reacts in terms of which part of the structure of a molecule changes, how reagents react and what reagents the molecule will react with. The more electronegative atom carries the ^d- charge e.g. ...

    • The C^δ+ in the polar bond C^δ-Cl^δ- in halogenoalkanes are susceptible to nucleophilic attack by electron pair donors.   (see mechanisms Part II)

    • The C^δ+ in the polar bond >C^δ+=O^δ- in aldehydes/ketones/acyl chlorides etc. are susceptible to nucleophilic attack by electron pair donors.   (see mechanisms Part III)

    • The polarised hydrogen bromide molecule, H^δ+-Br^δ-, acts as an electrophile by proton donation in which the proton (H atom) of the HBr acts as a H⁺ ion and accepts a pair of electrons to form an C-H bond.   (see mechanisms Part Ib)

• electrophile: A 'reagent' atom, ion or molecules that can accept a pair of electrons (Lewis acids) from an 'electron rich' part of a molecule like the ∏ electrons of an alkene or arene. They acts as Lewis acids, electron pair acceptors when interacting with molecules such as alkenes and arenes.   (see alkene mechanisms or aromatic mechanisms)

  • e.g. Br₂, CH₃CH₂⁺, Br⁺, SO₃, H-OSO₂OH, H^δ+-Br^δ-

• electrophilic attack: The interaction of an electrophile reagent (electron pair acceptor) interacting with an electron pair donor prior to forming the products of that mechanism step e.g. 'attacks' on .... 

  • Alkenes or or  

    • above are three examples of electrophilic attack on alkenes (see alkene mechanisms)

  • Arenes or or or

    • and four examples of electrophilic attack on benzene, the simplest arene or aromatic hydrocarbon.  (see aromatic mechanisms)

• electrophilic addition: An electrophilic reagent adds to a molecule to give the product (without any elimination).

  • e.g. hydrogen bromide adding to an alkene >C=C< + HBr => >CH-CBr<.

    • (see alkene mechanisms)

• electrophilic substitution: An electrophilic reagent replaces an atom or group of atoms in another molecule.

  • e.g. the nitration of benzene. C₆H₆ + HNO₃ ==> C₆H₅NO₂ + H₂O

  • where a H in the benzene ring replaced by NO₂ via the electron pair accepting electrophile, the NO₂⁺ ion.

    • (see aromatic mechanisms)

• elimination reaction: A small molecules is eliminated from a larger molecule, often by combining two fragments from adjacent atoms e.g.

  • >CH-C(OH)< ==> >C=C< + H₂O (see alcohol mechanisms)

  • >CH-C(Br)< + KOH ==> >C=C< + H₂O + KBr (see halogenoalkane mechanisms)

• free radical: An atom or fragment of a molecule with an unpaired electron, often shown by a dot. (see alkane mechanisms)

  • They are usually highly reactive species e.g. a chlorine atom Cl^. or a methyl radical CH₃^. 

• functional group:  (see summary of functional groups)

• heterolytic bond fission: see bond fission

• homolytic bond fission: see bond fission

• hydrolysis: A reaction, usually in aqueous media, between one molecule and water/acid/alkali which leads to the formation of at least two products e.g.

  • the tertiary halogenoalkane 2-chloro-2-methylpropane, reacts with water to form 2-methylpropan-2-ol and hydrochloric acid. (see halogenoalkane mechanisms)

    • (CH₃)₃C-Cl + 2H₂O ==> (CH₃)₃C-OH + H₃O⁺ + Cl^- 

  • The ester methyl ethanoate forms sodium ethanoate and methanol when refluxed with aqueous sodium hydroxide.

    • CH₃COOCH₃ + NaOH ==> CH₃COONa + CH₃OH

  • Aliphatic acid/acyl chlorides readily hydrolyse back to the parent carboxylic acid with water. (see mechanisms Part III)

    • RCOCl + 2H₂O ==> RCOOH + H₃O⁺ + Cl^- 

• initiation step: The name of the 1st step in a reaction mechanism sequence. The term is usually applied to the 1st step in free radical chain reactions, when the initial radicals are formed. (see alkane mechanisms)

  • e.g. in the chlorination of methane the 1st step is: Cl₂ ==hv==> 2^.Cl when a uv photon splits the chlorine molecule

  • or an organic peroxide splitting on heated to give two alkoxy radicals : RO-OR ==> 2RO^. 

• isomeric products: This means two or more products from the same reaction which have the same molecular formula but different molecular structure (positional isomerism/isomerizm). [see detailed notes on ISOMERISM]

  • This can happen when e.g. an unsymmetrical reagent like HX adds to an unsymmetrical alkene, because you can theoretically add H-X or X-H across a R₂C=CR'₂  double bond where R and R' are different e.g. with hydrogen bromide

    •  R₂C=CR'₂ + HBr ==> {R₂CH-CBrR'₂ or R₂CBr-CHR'₂}

• Lewis acid: An atom, ion or molecule that can accept a pair of electrons to form a bond. Electrophiles are Lewis acids.

  • e.g. organic reaction examples include Br⁺, CH₃⁺, or the polar H^δ+-Br^δ- and H^δ+-O^δ-SO₂OH (H₂SO₄)

• Lewis base: An atom, ion or molecule that can donate a pair of electrons to form a bond. Nucleophiles are Lewis bases.

• Markownikoff Rule (Markownikov/Markovnikov): This is a rule that predicts the orientation of electrophilic addition of an electrophile like H^δ+Br^δ- or I^δ+Cl^δ+ (in general lets call it W^δ+-X^δ-) to a non-symmetrical alkene and it can be expressed in several ways (see alkene mechanisms) e.g.

  • The negative part of the addendum, W^δ+-X^δ-, attaches itself to the carbon atom of the double bond which initially has the least hydrogen atoms bonded it to it.

  • So for an non-symmetrical alkene like propene, you would expect the majority reaction to be ...

  • CH₃CH=CH₂ + W-X ==> CH₃CHX-CH₂W (much less of CH₃CHW-CH₂X, as you cannot assume zero probability of forming the other isomeric product!)

• mechanism: A detailed step by step representation of how a reaction actually takes place and is far more complicated that the 'usual' stoichiometric equation!  (lots of examples of organic mechanisms)

• molecularity : This can mean several things unfortunately and is frankly confusing at times.

  1. The number of species involved in a chemical change or reaction step. Since most reactions occur via one or more steps involving bimolecular collisions, so the molecularity is often 2.

  2. Some reactions, whose rate depends on just one reactant are described as 'unimolecular' or if the reaction depends on two reactant concentrations it may be described as 'bimolecular'. The use of the 'molecularity' here has more to do with kinetic studies of reactions (e.g. the nucleophilic substitutions of halogenoalkanes, see S_N1 and S_N2).

• non-polar bond: A bond where the to atoms have similar electronegativities and the bonding pair of electrons is 'equally shared'.

  • e.g. C-H, C-C, C-P etc. (see Pauling electronegativity scale above)

• non-symmetrical/unsymmetrical alkene: An alkene in which the groups attached to each carbon of the double bond are NOT identical. (see alkene mechanisms) e.g.

  • propene CH₃-CH=CH₂, methylpropene (CH₃)₂C=CH₂ or but-1-ene CH₂=CH-CH₂-CH₃ 

  • If an unsymmetrical reagent e.g. HX is added, two isomeric products can be formed.

  • e.g. CH₃-CH₂-CH₂X or CH₃-CHX-CH₃ from propene.

• nucleophile: An 'reagent' electron pair donor (Lewis base) that will 'attack' an electron deficient part of a molecule e.g. the 'positive' of polarised bonds W^δ+X^δ-, in halogenoalkanes C-X, or aldehydes/ketones >C=O or acyl (acid) chlorides RCOCl

  • e.g. hydroxide ion :OH^-, ammonia :NH₃, ethanol CH₃CH₂OH, water H₂O:, cyanide ion :CN^-

• nucleophilic addition: An nucleophilic reagent adds to a molecule (without any elimination). (see aldehyde/ketone mechanisms) e.g.

  • e.g. ethanol reacts with cyanide ions (the nucleophile) to form a hydroxynitrile

    • CH₃CHO + HCN ==> CH₃C(OH)CN 

• nucleophilic addition-elimination: A nucleophilic reagent adds to another molecule and then a small molecule is eliminated to give the final product.

  • e.g. ethanoyl chloride reacts with methanol to make methyl ethanoate and hydrogen chloride is eliminated in the process. The electron pair (on the oxygen) donating nucleophile is methanol. (see mechanisms Part III)

  • CH₃COCl + CH₃OH ==> CH₃COOCH₃ + HCl 

• nucleophilic attack: The interaction of a nucleophile reagent (electron pair donor) interacting with an electron pair acceptor prior to forming the products of that mechanism step e.g. 'attacks' on ...

  •  or or Halogenoalkanes - 3 examples

     

  • or Aldehydes and ketones - 2 examples

     

  • or Acyl chlorides - 2 examples

     

• nucleophilic substitution: A nucleophilic reagent replaces an atom or group of atoms in another molecule.

  • e.g. halogenoalkanes react with electron pair donating reagents (see nucleophilic attack above).

• polar bond: A covalent bond in which the two atoms have different electronegativities leading to an unequal sharing of the bonding pair(s) of electrons.

  • e.g. a carbon-chlorine bond C^δ+-Cl^δ- or the carbon-oxygen double bond (carbonyl) >C^δ+=O^δ- 

    • See Pauling electronegativity scale above.

• primary (prim or 1^o): A structural term in organic chemistry to indicate no or just one alkyl/aryl group are attached to the carbon or nitrogen atom of the functional group e.g.

  • bromomethane CH₃Br and 1-chloropropane CH₃CH₂CH₂Cl are primary halogenoalkanes

  • methylamine CH₃NH₂ and propylamine CH₃CH₂CH₂NH₂ are primary aliphatic amines

  • methanol CH₃OH and butan-1-ol CH₃CH₂CH₂CH₂OH are primary alcohols

  • CH₃⁺ and CH₃CH₂CH₂⁺ are primary carbocations

  • see also secondary and tertiary for comparison

• propagation step: Type of mechanism step in free radical chain reactions, where a radical reacts with a substrate molecule, but also/only produces another reactive free radical which continues the reaction .e.g.

  • CH₃^. + Cl₂ ==> CH₃Cl + ^.Cl (which produces the product in the chlorination of methane AND a reactive chlorine radical)

  • RO-CH₂-CH₂^. + CH₂=CH₂ ==> RO-CH₂-CH₂-CH₂-CH₂^. (in the free radical polymerization of alkenes, a peroxide radical adds to an alkene (1st reactant on left) and this radical adds to another alkene molecule (right product) which is itself a radical and continue reaction building up the polymer chain until terminated!)

• protonation: Adding a proton, H⁺, to a species e.g.

  • CH₂=CH₂ + H₂SO₄ ==> CH₃-CH₂⁺ + HSO₄- (in the electrophilic addition of sulphuric acid to alkenes)

  • CH₃CH₂OH + H₃O⁺ ==> CH₃CH₂OH₂⁺ + H₂O (in the OH substituted reactions of alcohols)

• quaternary (quat or 4^o): The term used to describe the alkylammonium salts formed when nitrogen is bonded to four alkyl groups i.e. all four hydrogens on the ammonium ion are replaced by alkyl groups.

  • [(CH₃)₄N]⁺Cl^- is tetramethylammonium chloride, and can be formed by multiple nucleophilic substitutions happen when e.g. bromoethane is reacted with ammonia.

• secondary (sec or 2^o): A structural term in organic chemistry to indicate two alkyl/aryl groups are attached to the carbon or nitrogen atom of the functional group e.g.

  • 2-chloropropane CH₃CHClCH₃ is a secondary halogenoalkane

  • diethylamine (CH₃CH₂)₂NH is a secondary aliphatic amine

  • CH₃CH⁺CH₃ is a secondary carbocation

  • butan-2-ol CH₃CH₂CHOHCH₃ is a secondary alcohol

  • see also primary and tertiary for comparison

• shift of electrons: see use of arrows in mechanisms

• S_N1: Shorthand for a nucleophilic substitution reaction in which the rate determining step is the formation of carbocation from just one of the reactant molecules or intermediates (X) and the rate is independent any other reactant or intermediate.

  • This results in overall 1st order reaction kinetics: e.g. rate = k₁[X]

    • and sometimes referred to as a 'unimolecular' reaction. (see mechanisms Part II)

• S_N2: Shorthand for a nucleophilic substitution reaction in which the rate determining step is a bimolecular collision of two reactant molecules (X and Y) and the rate is independent any other reactant or intermediate.

  • This results in overall 2nd order reaction kinetics: e.g. rate = k₂[X][Y]

    • and sometimes referred to as a 'bimolecular' reaction. (see mechanisms Part II)

• stereospecific/stereospecificity: means the change reactants ==> products is dependent in some way on the spatial orientation of at least one of the reactants or intermediates, e.g. in the key-lock mechanism of enzymes, the 'key into lock' interaction, i.e. the stereospecificity of enzymes, partly depends on the spatial orientation of the enzyme's protein structure and the shape of the substrate molecule, particularly from the point of view of bond formation or the inter-molecular force of hydrogen bonding.

• steric hindrance: This means a reaction is inhibited because of some spatial/orientation limitation, e.g. bulky groups attached to an atom/bond that theoretically is susceptible to attack by a particular reagent.

• substitution: When one atom or group of atoms is replaced by another atom or group of atoms. (see mechanism index for lots of examples)

• symmetrical alkene: An alkene in which the groups attached to each carbon of the double bond are identical. (see alkene mechanisms) e.g.

  • ethene H₂C=CH₂ or but-2-ene CH₃-CH=CH-CH₃ 

  • If an unsymmetrical reagent e.g. HX is added, only one product is formed.

  • e.g. CH₃-CH₂X or CH₃-CH₂-CHX-CH₃ from ethene or but-2-ene.

• termination step : A step in a free radical chain reaction in which two radicals combine to bring that particular 'chain' to a halt.

  • e.g. in the chlorination of methane two methyl radicals can combine to form ethane. (see mechanisms Part Ia)

    • 2H₃C^. ==> H₃C-CH₃ 

• tertiary (tert or 3^o): A structural term in organic chemistry to indicate three alkyl or aryl groups are attached to the carbon or nitrogen atom of the functional group e.g.

  • 2-chloro-2-methylpropane (CH₃)₃CCl is a tertiary halogenoalkane

  • trimethylamine (CH₃)₃N: is a tertiary aliphatic amine

  • 2-methylpropan-2-ol (CH₃)₃COH is a tertiary alcohol

  • (CH₃)₂C⁺CH₂CH₃ is a tertiary carbocation

  • see also primary and secondary for comparison

• transition state: see activated complex above

• 'unimolecular' mechanism/kinetics : see S_N1

• unsymmetrical alkene: structure and addition to, see non-symmetrical alkene

• I hope this page will help with the following GCE-AS-A2-IB Advanced/Subsidiary Level Chemistry syllabuses

  • Salters Chemistry: Chemistry 3887/7887 5.3.20 Organic Reaction Mechanisms, unit/module A Atmosphere, PR Polymer Revolution, What's in a Medicine, MD Medicine by Design

  • OCR Chemistry: 3882/7882 module 2812 Chains and Rings, 2814 Chains, Rings and Spectroscopy

  • Edexcel Chemistry 8080/8090 Topic 2.2 Organic Chemistry I (Introduction, alkanes, alkenes, halogenoalkanes), Topic 4.5 Organic Chemistry II (acids, esters, carbonyl compounds, acid chlorides, nitrogen compounds, and further halogeno-compounds, Topic 5.3 Organic chemistry III (reaction mechanisms and aromatic compounds)

  • Nuffield Chemistry: 8086/9086 Unit 1 Introductory Chemistry Topic 2 Alcohols: an introduction to organic chemistry, Unit 2 Bonding and reactions: Topic 8 Organic Chemistry: Hydrocarbons, Topic 10 Halogenoalkanes (haloalkanes), Unit 4 Energy and reactions: Topic 12 Arenes: benzene and phenol

  • AQA Chemistry: 5421/6421 Module 3 Introduction to Organic Chemistry/Practical: Chlorination alkanes, alkene reactions, haloalkanes, alcohols; Module 4 Further Physical and Organic Chemistry: aldehydes and ketones reactions, carboxylic acids and esters, acylation, aromatic chemistry, amines

  • International Baccalaureate Chemistry: Topic 16 Kinetics: 16.2 Reaction Mechanism; Topic 20 Organic Chemistry: 20.2 Hydrocarbons, 20.3 Nucleophilic substitution reactions, 20.4 Alcohols; Option A Higher Physical Organic Chemistry A.3 Reaction Mechanism, A.4 Nucleophilic substitution reactions; Option E Chemical Industries: Topic E.8 Mechanisms in the Organic Chemicals Industry; Option H Further Organic Chemistry: H.2 Free Radical Substitution Reactions, H.3 Electrophilic Addition Reactions, H.4 Electrophilic Substitution Reactions, H.5 Nucleophilic Addition Reactions, H.6 Nucleophilic Substitution Reactions, H.7 Elimination Reactions, H.8 Addition-elimination Reactions.

GENERAL REVISION NOTES

for studying revising tutoring teaching Advanced Level GCE AS A2 IB CHEMISTRY courses in unofficial support the Chemistry in any advanced-subsidiary AQA, EDEXCEL, OCR, SALTERS, CIE, WJEC, SQA and CCEA (NI) UK or Cambridge/London/Edexcel International and OCR/CIE International examinations

*  revision  notes for advanced level chemistry course *  revision notes for advanced level chemistry course *   revision notes for advanced level chemistry course *   revision notes for advanced level chemistry course *  revision  notes for advanced level chemistry course *   revision notes for advanced level chemistry course *  revision  notes for advanced level chemistry course *  scientific investigations, educational development, scientific exhibitions, scientific adventures, science projects, fantasy science, science fiction, interesting science demonstrations, fascinating science experiments, science education conferences, scientific expeditions, scientific information and databases, revision tutoring resources for syllabuses specifications examinations, chemical physical biological forensic science, scientific applications, science-chemistry tuition courses *  revising AS A2 IB GCE advanced level chemistry at Doc Brown's Chemistry Clinic *  revising AS A2 IB GCE advanced level chemistry at Doc Brown's Chemistry Clinic * revising AS A2 IB GCE advanced level chemistry at Doc Brown's Chemistry Clinic *  revising AS A2 IB GCE advanced level chemistry at Doc Brown's Chemistry Clinic * revising AS A2 IB GCE advanced level chemistry at Doc Brown's Chemistry Clinic *  revising AS A2 IB GCE advanced level chemistry at Doc Brown's Chemistry Clinic *  revising AS A2 IB GCE advanced level chemistry at Doc Brown's Chemistry Clinic *  revising AS A2 IB GCE advanced level chemistry at Doc Brown's Chemistry Clinic * revising AS A2 IB GCE advanced level chemistry at Doc Brown's Chemistry Clinic *  revising AS A2 IB GCE advanced level chemistry at Doc Brown's Chemistry Clinic *  revision notes for advanced level chemistry course *  revision notes for advanced level chemistry course *   revision notes for advanced level chemistry course *  revision  notes for advanced level chemistry course *  revision  notes for advanced level chemistry course *  revision  notes for advanced level chemistry course *   notes for advanced level chemistry course *