Ch10. Organic Chemistry
Go to Definitions
Go to Handouts
Go to Presentations
Go to Simulations
Go to Videos
Go to Podcasts
Go to Links
Definitions
Benzene: Hexagonal shape with delocalized π bonds. Undergo substitution rather than addition reactions.
Boiling and melting point: Depend on intermolecular forces. The greater the intermol. forces, the higher the m.p. and b.p.
Bromination: Yellow/orange bromine is decolorized when added to an alkene due to addition reaction. Used to test for alkenes.
Carbocation: A cation in which the carbon carries most of the + charge. Can be formed during SN1 substitution.
Chiral center: An asymmetric carbon atom, i.e. has four different groups of atoms attached to it.
Cis-isomer: The geometric isomer in which the similar groups are on the same side of the double bond. Commonly polar.
Condensation reaction: Reaction in which two molecules join together with the loss of a small molecule, typically water.
Dehydration: Loss of water. Alcohols can be dehydrated when they are refluxed with condensed sulphuric acid.
Esterification: Process by which an alcohol and a carboxylic acid are converted into an ester and water, with sulphuric acid catalysis.
Fission, heterolytic: Bond breaking in which the more electronegative of the two atoms joined by the bond takes both of the electrons.
Fission, homolytic: Bond breaking in which each atom takes one of the e- in the bond, creating free radicals.
Free radical: A species containing at least one unpaired electron, as a result of homolytic fission. Very reactive.
Halogenoalkane, primary: Halogenoalkanes that have one alkyl group attached to the carbon atom bonded to the halogen. Undergo SN2 mechanism in nucleophilic substitution.
Halogenoalkane, tertiary: Halogenoalkanes that have three alkyl groups attached to the carbon atom bonded to the halogen. Undergo SN1 mechanism in nucleophilic substitution.
Homologous series: A group of compounds where neighbouring members differ by –CH2. Have similar chemical properties, but gradually changing physical properties.
Hydration: Addition of water. Ethanol can be formed from addition of water to ethene.
Hydrocarbon: Compounds containing only carbon and hydrogen.
Hydrogenation: Addition of hydrogen. Can be used to reduce number of double bonds in polyunsaturated vegetable oils present in margarine, causing it to become a solid at room temperature.
Hydrolysis: Process by which a molecule is broken down by water.
Isomers: Different compounds that have the same molecular formula but different structure.
Isomers, functional group: Where the isomers contain different functional groups.
Isomers, hydrocarbon chain: Where there is a difference in the structure of the hydrocarbon chain.
Isomers, optical: Where a molecule shows optical activity in its mirror images. Enantiomers rotate the plane of polarization of light in different directions. Occurs when there is one or more chiral centers.
Isomers, positional: Where the position of the functional group is different.
Isomers, stereo-: Where the molecules have a different spatial arrangement of atoms and hence different 3D shapes. Subdivided into geometric and optical isomers (enantiomers).
Isomers, structural: Where the atoms have a different structural formula altogether. Subdivided into positional, hydrocarbon chain and functional group isomers.
Mechanism, SN1: A unimolecular process by which a halogenoalkane undergoes nucleophilic substitution. A two-step mechanism: a rate-determining step in which the bond between the carbocation and the halogen are broken, followed by a step in which the nucleophile is attracted to the carbocation. Faster than SN2, as the formation of the intermediate carbocation is faster than the SN2 route which involves a transition state with relatively high activation energy.
Mechanism, SN2: A bimolecular process by which a halogenoalkane undergoes nucleophilic substitution. Mechanism involves formation of a transition state which involves both of the reactants.
Monomer: Components of a polymer.
Nucleophile: The species that donates the electron pair in an organic chemical reaction. A nucleophile is also a Lewis base. Typical nucleophiles are CN-, OH- and NH3.
Nucleophilic substitution: Substitution that occurs with a halogenoalkane reacting with a nucleophile.
Peptide bond: -C=ONH-. Bond formed as the result of condensation reaction between a carboxyl group and an amino group.
Peptide, di-: Two amino-acids joined together.
Peptide, poly-: More than 20 amino-acids joined together.
Peptide: Molecule formed by aminoacids joined together by peptide bonds (by condensation reaction in which water is lost).
Polymer: Very long molecule made up of repeating units.
Polymerization, addition: Forming a polymer by addition of monomers.
Polymerization, condensation: Forming a polymer by substitution reaction between monomers, each having two functional groups.
Reaction, addition: A reaction in which the reactant is added across a C=C bond, converting it to a C-C bond. Addition reactions with water requires an H2SO4 catalyst. Addition reactions with hydrogen use Ni as catalyst.
Reaction, substitution: A reaction in which one group is substituted for another. Substitution reactions with halogenoalkanes are nucleophilic substitutions. Benzene does not undergo substitution reactions readily as its π bonds are delocalized.
Reflux: A condenser which causes any vapour produced to condense and returns to the flask and continues to react. If the carboxylic acid is desired from the oxidation of a primary alcohol, this must be done under reflux. On the other hand, if the aldehyde is desired, this can be distilled from the reaction mixture as soon as it is formed.
Saturated: Containing only single bonds. Alkanes are saturated.
Spectrometry, mass: Separating ions according to mass.
Spectroscopy, IR: Analyzing the bonds present within a molecule by sending infrared light through it, causing the bonds to absorb radiation of characteristic frequencies.
Spectroscopy, NMR: Analysis of hydrogen environments to deduce the structure of a molecule.
Trans-isomer: The geometric isomer in which the similar groups are on different sides of the double bond. Commonly non-polar.
Unsaturated: Containing double bonds between carbon aoms. Alkenes are unsaturated. Can be tested for by bromination.
•Summary of Sn1, Sn2, E1, E2 reactions [.pdf]
•Naming organic compounds [.pdf]
Presentations
•Stereoisomers [.pdf]
•Radical substitution on alkanes [link]
•Sn2 nucleophilic substitution on halogenalkanes [link]
•E1 nucleophilic elimination on halogenalkanes [link]
•E2 nucleophilic elimination on halogenalkanes [link]
Videos
•Optical isomerism
Podcasts
•Functional Groups of Organic Compounds [link]
