Organic chemistry

Subdecks (1)

Cards (331)

  • Homolytic fission occurs when each atom in a covalent bond gets one electron, producing free radicals.
  • Heterolytic fission occurs when one atom gets both electrons when a covalent bond is broken, producing free radicals.
  • Free radicals are reactive species which possess an unpaired electron.
  • The type of reaction that occurs between a halogen and an alkene is Free Radical substitution.
  • The conditions for Halogenation are UV light, Alkane + halogen (eg Br2), and the three stages of Halogenation are initiation reactions, propagation reactions, and termination reactions.
  • A double bond is made up of a sigma-bond and a pi-bond.
  • Alkenes are more reactive due to the pi-bond in the double bond, which is formed from the overlap of p-orbitals.
  • The pi-bonds in alkenes are much weaker than sigma-bonds due to the spread of electron density above and below the molecule, making it more likely to be attacked by electrophiles.
  • An electrophile is an electron-pair acceptor.
  • The type of reactions alkenes go through are Electrophilic addition reactions.
  • Markownikoff's rule states that H adds to the carbon with the most H atoms already attached as this is the more stable carbocation.
  • The more alkyl groups on a carbocation, the more stable it is because the alkyl groups are electron-releasing and reduce the charge on the positive carbon atom, stabilising it.
  • The test for a C=C double bond is to shake the alkene with orange bromine water, and if it goes colourless, it indicates the presence of a double bond.
  • The production of alkanes from alkenes involves reagents such as Alkene + Hydrogen, Ni catalyst, 150 degrees Celsius, and the reaction taking place is Hydrogenation.
  • The formation of alcohol from an alkene involves reagents such as alkene and steam, at 300 degrees Celsius, 60-70 atm, and the reaction taking place is Hydration.
  • The products of complete combustion of alcohols are carbon dioxide and water.
  • The formation of haloalkanes from alcohols involves reagents such as alcohol and halide ion, acid catalyst (H2SO4), and the reaction taking place is Halogenation.
  • Dehydration of alcohols involves reagents such as alcohol and conc H2SO4, and the reaction taking place is Elimination reaction.
  • The oxidation of Primary Alcohols involves reagents such as alcohol and potassium dichromate solution [O], distillation for aldehyde, reflux for carboxylic acid, and the observation is the reduction of the orange dichromate(VI) ion to the green chromium(III) ion, Cr3+.
  • The oxidation of Secondary Alcohols involves reagents such as alcohol and potassium dichromate solution [O], distillation for ketone, and the observation is the reduction of the orange dichromate(VI) ion to the green chromium(III) ion, Cr3+.
  • The oxidation of Tertiary Alcohols cannot be oxidised.
  • A haloalkane is an alkane with halogen atoms.
  • A nucleophile is an electron-pair donator.
  • Halogens are much more electronegative than C, so the C-X bond in haloalkanes is polar.
  • The delta+ C in haloalkanes is electron deficient, so attracts nucleophiles to undergo nucleophilic substitution reactions.
  • Aromatic compounds contain a benzene ring.
  • In benzene, electrons are delocalised, while in alkenes, they are localised between two carbon atoms.
  • Benzene is more stable than alkenes because it has a lower electron density.
  • In benzene, electrons are delocalised, while in alkenes, they are localised between two carbon atoms.</flashcard
  • Benzene is a delocalised system made up of two rings of delocalised electrons above and below the plane of the molecule.
  • All C-C bonds in benzene are 140pm, which is different from the normal length of 154pm for C-C bonds and 134pm for C=C bonds.
  • Benzene is unwilling to undergo addition reactions because it is too stable.
  • Benzene is more stable than alkenes because in benzene, electrons are delocalised, while in alkenes, they are localised between two carbon atoms.
  • The enthalpy change of hydrogenation for cyclohexene is -120 kJ/mol, which is less exothermic than expected.
  • Benzene has a lower electron density than alkenes, so it is unwilling to undergo addition reactions because it is too stable.
  • Radical substitution in alkanes results in the conversion of an alkane into a haloalkane, with halogen (X 2 ) as the reagent and UV radiation as the condition.
  • Hydrogenation in alkenes results in the conversion of an alkene into an alkane, with hydrogen (H 2(g) ) as the reagent and a Ni catalyst (at 423 K) as the condition.
  • Dihalogenation in alkenes results in the conversion of an alkene into a dihaloalkane, with halogen (X 2 ) as the reagent and no conditions specified.
  • Halogenation in alkenes results in the conversion of an alkene into a haloalkane, with hydrogen halide (HX) as the reagent and no conditions specified.
  • The general equation for nitrile reduction is RCN + 2H2RCCH2NH2.