DF 3 (prep yourself) Flashcards
what are petrol and diesel mixtures of
complex mixtures of many different compounds carefully blended to give the right properties
compounds obtained from crude oil
what is crude oil and its physical state
its a mixture of many hundreds of hydrocarbons
its a thick back liquid with dissolved gases and solids
how are the sources of petrol components obtained from crude oil
-oil from the north sea pumped to UK refineries
-crude oil heated to vaporise, then passed into distillation column
-separated into fractions, with certain ranges of boiling points
-gasoline and gas oil fractions are sources for festival components
why do fractions not have exact boiling points
because they are mixtures of many different hydrocarbons
what does organic chemistry entail and why
includes all carbon compounds because many carbon compounds are found in living organisms
-except carbon monoxide, carbon dioxide and the carbonates
why do the properties of carbon make it so important
-first element of group 4, so it has 4 electrons in its outer shell, must lose or gain 4 electrons to be stable, but the charge would be too high
-so it forms covalent bonds instead
-forms strong covalent bonds with itself to form C-C covalent bonds (catenation)
-can form limitless variety of organic compounds
what is a hydrocarbon
-compounds containing ONLY hydrogen and carbon
what is an aromatic compound
compound that contains one or more benzene rings
hat is an aliphatic compound
compounds that don’t contain benzene rings
what is a functional group
modifiers that are responsible for the characteristic chemical reactions of molecules
name the formula, shape and type of compound of the following compounds
-benzene
-methane
-cyclohexane
-ethene
BENZENE C6H6
-circle surrounded by hexagon
-arene
METHANE CH4
-carbon surrounded by 4 hydrogens (cross like) of single bonds
-alkane
CYCLOHEXANE C6H12
-hexagon
-cycloalkane
ETHENE C2H4
-carbon double bond, 2 diagonal hydrogens on each carbon
-alkene
why does the benzene have the ring in the middle
each carbon in the hexagon of carbons makes three bonds and leaves one delocalised electron each in the centre to form a ring of them
how do hydrocarbons, specifically alkanes and arenes become reactive
they are unreactive frameworks of hydrocarbons
modifiers
when other groups are attached the properties are modified
modifiers are also known as the functional group
what is an alkane and describe the properties e.g formula
saturated hydrocarbons, so they contain the maximum number of hydrogen atoms possible without any carbon double or triple bonds
-formula Cn H 2n+2
-cracked to form alkenes
-they can be branched
-react with oxygen to make CO2 and 02
-can be isomerised
what is a homologous series
a series of compounds in which all members have the same general formula and functional group
they all have similar chemical properties but different physical properties e.g melting and boiling points and density
what is the molecular, full structural, shortened structural and further shortened formula of ethane
molecular formula: C2H6
full structural 2 carbons each attached to 3 hydrogens (up, down, left, right) by single bonds
shortened structural formula: CH3-CH3
further shortened: CH3CH3
what is a structural isomer
when two compounds have the same molecular formula and a different structural isomer
name the first 6 alkyl groups
CH3 methyl
CH3 CH2 ethyl
CH3 CH2 CH2 propyl
CH3 CH2 CH2 CH2 butyl
CH3 CH2 CH2 CH2 CH2 pentyl
what are cycloalkanes
alkanes in a cyclic structure that are saturated
state the molecular formula of cyclobutane and cyclohexane
cyclobutane - C4H8
cyclohexane- C6H12
how to name branched alkanes
- find the LONGEST chain e.g. hexane
- identify the side chains e.g. butyl
3.state the location of the side chain by the numbered carbon on the longest chain, trying to make the carbon number as low as possible
e.g. 2-butylhexane - if there’s more than one side chain, keep numbers low as possible still and put them in alphabetical order
- name the location of the side chains first with commas in between the no. s
e.g 2,2-dimethyl propane
describe the physical state of the first few alkanes
-first four of the series are colourless gases
-numbers 5-16 are colourless liquids
- numbers 17+ are white waxy solids
how do alkanes mix with each other and water (why)
- mix well with each other
-do not mix well with water, form two separate layers because alkanes contain non polar molecules but water contains polar molecules which attract each other and prevents the alkanes molecules mixing with them
