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 + 2H2 → RCCH2NH2.