Unit seven JCL Flashcards
carbon bond angle (tetrahedral)
109.5
what is a hydrocarbon
Hydrogen and carbon
Aliphatic Hydrocarbon
The carbon atoms are joined by straight or branched chains
Alicyclic Hydrocarbon
A sub-group of aliphatic hydrocarbons, carbon atoms are joined in a ring structure
Aromatic Hydrocarbon
Contains a benzene ring
Functional group definition
A group of atoms responsible for the characteristic reactions of a molecule
Homologous series definition
A series of organic compounds that have the same functional group but with each successive member differing by CH2
Empirical formula definition
The simplest whole number ratio of atoms of each element present in a compounds eg CH2
Molecular formula definition
The actual number of atoms of each element in a molecule
General formula definition
The simplest algebraic formula of a member of a homologous series, ie for an alkane CnH2n+2
Structural formula definition
The minimal detail that shows the arrangement of atoms in a molecule
Displayed formula definition
The relative positioning of atoms and the bonds between then, all bonds shown
Skeletal formula definition
The simplified organic formula, shown by removing hydrocarbon atoms from alkyl chains
Molecular formula of methane
CH4
Molecular formula of ethane
C2H6
Molecular formula of propane
C3H8
Molecular formula of butane
C4H10
Molecular formula of pentane
C5H12
Molecular formula of hexane
C6H14
Isomer definition
Isomerism is where two or more compounds have the same molecular formula but different arrangement of their atoms. Isomers have different physical and chemical properties
Structural isomer definition
Molecules with the same molecular formula but with different structural arrangement of atoms
Chain isomerism definition
The carbon chain of molecules with the same molecular formula can vary causing isomerism
Positional isomerism definition
Functional groups can be in different positions on the carbon chain causing isomers
Functional group isomerism definition
Compounds with the same molecular formulae can contain different functional groups
Homolytic fission definition
The breaking of a covalent bond with one of the bonded electrons going to each atom, forming 2 radicals
Heterolytic fission definition
The breaking of a covalent bond with both of the bonded electrons going to one of the atoms forming a cation (positive ion) and an anion (negative ion)
Radical definition
A highly reactive species due to it having an unpaired electron
What does the base of a curly arrow show
The origin of the electron(s)
What does the head of a curly arrow show
The destination of the electron(s)
Nucleophile definition
An electron pair donor
Electrophile definition
An electron pair acceptor
Alkenes suffix/prefix
suffix -ene
Alcohols suffix/prefix
suffix* -ol
prefix hydroxy-
Haloalkanes suffix/prefix
prefix Chloro-
Bromo-
Iodo-
Fluoro-
Aldehydes suffix/prefix
suffix -al
Ketones suffix/prefix
suffix* -one
prefix oxo-
Carboxylic acids suffix/prefix
suffix -oic acid
Nitriles suffix/prefix
suffix -nitrile
Amines suffix/prefix
suffix* -amine
prefix amino-
Esters suffix/prefix
suffix -oate
Amide suffix/prefix
suffix -amide
Acyl chloride suffix/prefix
suffix -oyl chloride
Acid anhydride suffix/prefix
suffix -oyl anhydride
Addition reaction
A reaction in which a reactant is added to an unsaturated molecule to make a saturated molecule
Substitution reaction
A reaction in which an atom or group of atoms is replaced with a different atom or group of atoms
Elimination reaction
The removal of a molecule from a saturated molecule to make an unsaturated molecule
Alkane general formula
CnH2n+2
Why do alkanes have an angle of 109.5 between bonds
Electron Pair Repulsion theory
VSEPR theory
What is the trend in boiling point of straight chain alkanes
The longer the carbon chain, the higher the boiling point
chain length increases -> increased surface area between molecules -> strength of London forces increases
What is the trend in boiling point of branched alkanes
The more branches in the carbon chain, the lower the boiling point
(branching increases -> decreased surface area between molecules -> strength of London forces decreases)
What does a double-headed curly arrow represent
movement of a pair of electrons
Are alkanes reactive
quite unreactive, c-c and c-h bonds are very strong, c-c bonds are non-polar and c-h bonds are practically non-polar because of similarity in electronegativity
Free radical substitution steps
Initiation, Propagation, Termination
What type of molecule can be produced from alkanes through free radical substitution
Haloalkanes
How is a free radical produced
UV light causes homolytic fission
What happens to covalent bonds in diatomic halogen molecules in the presence of UV light
In the presence of UV light, the covalent bonds in diatomic halogen molecules will break, allowing a reaction with an alkane
What happens in the initiation step
UV light is used to split the bond in a diatomic halogen molecule (e.g. Cl2). The bond splits by homolytic fission. Two halide radicals are produced (e.g. Cl•)
What happens in the first propagation step
The halide radical (Cl•) that is produced in the initiation step reacts with an alkane (e.g. methane) to produce a hydrogen halide (e.g. HCl) and an organic radical (e.g. •CH3)
What happens in the second propagation step
The organic radical (e.g. •CH3) produced in the first propagation step reacts with a halogen molecule (e.g. Cl2). The result of the second propagation step is a haloalkane (e.g. CH3Cl) and the halide radical (e.g. Cl•) that was produced in the initiation step is reformed
What happens in the termination step
Two radicals react together to produce a stable molecule i.e. something that is not a radical. There can be several different termination steps as any two radicals can randomly react together to produce a stable molecule
