organic 1 p2 Flashcards
nomenclature
system used for naming organic compounds
empirical formula
simplest whole number ratio of atoms in a molecules
molecular formula
provides the actual number of atoms of different elements in a molecule
displayed formula
shows every atom and every bond in a molecule
structural formula
shows the arrangement of atoms in a molecule without showing every bond
skeletal formula
a type of formula which is drawn as line with each vertex being a carbon atom
carbon atoms not drawn, assumed each C atom has all unspecified bonds as C-H
homologous series
a series of organic compounds having the same functional group but with each successive member differing by CH2
functional group
a group of atoms responsible for characteristic reactions of a compound
suffixes for..
aldehyde
ketone
carboxylic acid
aldehyde = al
ketone = one
carboxylic acid = oic acid
alkane formula
CnH2n+2
alkene formula
CnH2n
saturated
organic compounds which only contain single bonds
unsaturated compounds
organic compounds that contain at least one carbon carbon double covalent bond
structural isomerism
when molecules have the same molecular formula but different structural formula
what are 3 ways in which structural isomers can be formed?
1 alkyl groups can be in different places
2 functional groups can be bonded to different parts
3 there can be different functional groups
stereoisomers
organic compounds with the same molecular formula but have different arrangement of atoms in space
what is E-Z isomerism and how are the E and Z isomers decided?
caused by limited rotation about the C=C double bonds
if the two substituents with the highest molecular mass are on the same side on the double bond (both above/both below) it is the Z isomer
what is cis-trans isomerism?
special type of E/Z isomerism where the two substituents of each carbon atom are the same
E - trans
Z - cis
homolytic fission
happens when each bonding atom receives one electron from the bonded pair forming two radicals
heterolytic fission
when one bonding atom receives both electrons from the bonded pair
what are radicals?
highly reactive, neutral species
how is a covalent bond formed from two radicals?
radicals collide and the electrons are involved in the bond formation
how are alkane fuels obtained?
fractional distillation, cracking and reforming crude oil
fractional distillation process
1 oil pre heated and passed into a column
2 fractions condense at different temps (temp is hottest at bottom)
3 separation of the fuels depends on boiling point which depends son size of molecules - the larger the molecule the larger the London forces
4 similar molecules condense together and so are collected at the same fraction
5 small molecules condense at the top at lower temps and big molecules condense at the bottom at higher temps
cracking
process of converting large hydrocarbons to smaller molecules by breakage of C-C bonds
reforming crude oil
processing of straight chain hydrocarbons into branched chain alkanes and cyclic hydrocarbons for efficient combustion
shape and angle of an alkane?
tetrahedral
109.5
describe the sigma bond in alkane
the sigma bond is a covalent bond which has a direct overlap of the electron clouds of the bonding atoms
how reactive are alkanes?
very unreactive
what reactions do alkanes undergo?
combustion and reaction with halogens
what type of reaction is combustion?
oxidation reaction
what is complete combustion?
combustion that occurs with plentiful supply of air
what are the products of complete combustion when alkanes are used?
carbon dioxide and water
what is the colour of the bunsen flame during complete combustion?
blue flame
what is incomplete combustion and what products are formed in the case of alkanes?
combustion in a limited supply of oxygen
products: water, carbon dioxide and carbon monoxide
what type of hydrocarbon are most likely to undergo incomplete combustion?
longer chains
what are the pollutants formed in the combustion of alkanes?
carbon monoxide, oxides of nitrogen and sulfur, carbon particulates and unburned hydrocarbons
what is the environmental impact of carbon monoxide?
it is toxic/poisonous
what is the environmental impact of soot (carbon)?
asthma, cancer, global dimming
what are the environmental impacts of nitrogen oxides?
NO is toxic and can form smog
NO2 is toxic and acidic and forms acid rain
what are the environmental impacts of unbranched hydrocarbons?
they contribute towards formation of smog
what is the importance of catalytic converters?
these remove CO, nitrogen and unburned hydrocarbons (e.g. octane) from exhaust gases turning them into less toxic products CO2, N2 and H2O
what are biofuels?
fuels developed from renewable resources
alcohols and biodiesel are two examples of renewable plant-based fuels
what are the advantages of biofuels?
+
- reduces use of non-renewable fuels
- use of biodiesel is more carbon-neutral
- fossil fuels can be used feedstock for organic compounds
- less large scale pollution
what are the disadvantages of biofuels?
- less food crops may be grown because crops for biofuel would be grown instead
- reduction of rainforests have to be cut down to provide land
- shortage of fertile soils
how are haloalkanes formed from alkanes
radical substitution