Core Organic Chemistry Flashcards
What does nomenclature mean
The system used for naming organic compounds
What does the term molecular formula mean
The actual number of atoms of different elements in a molecule
Displayed formula
Shows every atom and bond in a molecule
Structural formula
Arrangement of atoms in a molecule without showing every bond
Skeletal formula
Drawn as lines with each vertex being a carbon atom
Homologous series
Organic compounds with the same functional group but each successive member differing by CH2
Functional group
A group of atoms responsible for characteristic reactions of a compound
Aliphatic hydrocarbon
Straight/ branched chained
Alicyclic hydrocarbon
Arranged in noon aromatic rings with or without side chains
Aromatic hydrocarbon
Contains at least one benzene ring
General formula alkanes
CnH2n+2
General formula alkenes
CnH2n
General formula alcohols
CnH2n+1OH
Structural isomers
Same molecular formula but different structural formula
3 ways structural isomers are formed
Alkyl groups in different places
Functional groups bonded to different parts
Different functional groups
Stereoisomers
Same molecular formula but different arrangement of atoms in space
E-Z isomerism
Caused by limited rotation about c=c bonds
If 2 substituents with the highest molecular mass are on the same side of the double bond it’s Z if on different side its E
Cis-trans isomerism
Type of E/Z isomerism where the 2 substituents on each carbon atom are the same
Homolytic fission
Each bonding atom receives one electron from the bonded pair forming two radicals
Heterolytic fission
One bonded atom receives both electrons
Radicals
Highly reactive neutral species
What is an alkane
Saturated hydrocarbon with only C-H bonds
Shape and angle of an alkane
Tetrahedral 109.5°
Describe the sigma bond in alkanes
Covalent bond with direct overlap of the electron clouds of the bonded atoms
Intermolecular forces alkanes have
London forces- the bonds are non polar
Boiling point as alkane chain length increases
Increases as there is more surface area and so more London forces so more energy needed to overcome the attraction
Branched molecules boiling points
Lower boiling point than straight b as fewer surface area so less London forces
Are alkanes soluble in water
Insoluble
How reactive are alkanes
Very unreactive
Product of complete combustion of alkanes
CO2 +H2O
How are halogenoalkanes formed
Radical substitution
What is required for alkanes to ready with halogens
UV light
Three stages of radical substitution
Initiation- breaking halogen bond
Propagation-products are formed but radicals remain
Termination- free radicals removed, stable products formed
What are alkenes
Unsaturated hydrocarbons containing at least 1 c=c bond
How is a pi bond formed
Electrons in adjacent p orbitals overlap above and below carbon atoms
Angle and shape of a double bond
Trigonal planar 120°
Alkenes more or less reactive than alkanes
More due to high electron density of double bond and pi bond is slightly easier to break
What is an electrophile
Species that are electron pair acceptors
Major products will be formed from which kinds of carbocations
Tertiary(or most stable available)
Conditions for electrophilic addition of water to an alkene
Steam in presence of acid catalyst reaction is called hydration
Products of hydration reaction
An alcohol
Conditions for electrophilic addition of a hydrogenhalide to an alkene
Hydrogen halide gases must be at room temperature
Reaction name when a halogen is added to an alkene
Halogenation
How can an alkene be converted into an alkane
Alkene+hydrogen= alkane
Hydrogenation
150°c nickel catalyst
What is an addition polymer
Many monomers bonded together via rearrangement of bonds without the loss of any atom or molecule
Ways plastics can be disposed
Landfill
Combustion
Electricity generation
Reuse
Recycle
Organic feedstock
Functional group in an alcohol
Hydroxyl group OH
Intermolecular forces alcohols have
Hydrogen bonding because of the electronegativity difference in the OH bond
Alcohols boiling points
Higher than alkanes because of hydrogen bonding
Are alcohols soluble
Soluble when short chain but not in long chain
What makes an alcohol primary
The carbon the OH is bonded to is only bonded to one other carbon atom
What makes an alcohol primary
The carbon the OH is bonded to is only bonded to one other carbon atom
What forms if you partially oxidise a primary alcohol
An aldehyde
Conditions to make an aldehyde
Dilute sulphuric acid, potassium dichromate distill product gentle heating
Full oxidation of a primary alcohol
Carboxylic acid
Conditions to make a carboxylic acid
Concentrated sulphuric acid, potassium dichromate, reflux,strong heating
Oxidation of a secondary alcohol
Ketone
Conditions to make a ketone
Concentrated sulphuric acid, potassium dichromate, strong heating
What is a dehydration reation
A reaction where water is lost to form an organic compound
Products of a dehydration reaction (alcohol)
Alkene and water
Conditions dehydration reaction (alcohol)
Conc sulphuric acid/phosphoric and and 170°c
Products halide substitution reaction (alcohol)
Haloalkene and water
What are haloalkanes
Saturated organic compounds containing at least one halogen atom
Intermolecular forces (haloalkanes)
Permanent dipole-dipole and London forces
Most important factor in determining halogen reactivity
The strength of carbon halogen bond
Define nucleophile
Electrons pair donor
Nucleophillic substitution
Nucleophile donates a lone pair to a slightly positive carbon atom and the nucleophile replaces the slightly negative atom
What is hydrolysis
A reaction where water is a reactant
What are CFC’s
Chlorine-flouro-carbons
Problem with CFC’s
Catalyse the breakdown of ozone via free radical substitution
What happens when a molecule absorbs infrared radiation
Makes covalent bond vibrate/ Stretching or bending motion
Factors affecting amount of vibration of a bond
Bond strength
Bind length
Mass of each atom in the bond
How does infrared spectroscopy work
Every bond has a unique vibration frequency
Bonds absorb radiation of the same frequency as them
Infrared radiation emergency from a sample is missing the frequencies that have been absorbed
What do the peaks on an IR spectrum represent
Absorbance of energy from the infrared radiation
Symbol of molecular ion
M+
Is fragmentation predictable
No because it can happen anywhere
In mass spectrometry how is a molecular ion represented
The peak with the highest mass/charge ratio
The molecular mass of the molecular ion is equal to what
The relative molecular mass of the compound
M/Z value of CH3
15
M/Z value of OH
17
Advantages of using mass spectrometry
Cheap
Small samples required
Disadvantage of mass spectrometry
Sample is completely destroyed