organics 4.5 Flashcards
what’s the composition of crude oil?
mixture of hydrocarbons
H & C
crude oil, hydrocarbons:
different hydrocarbons have a huge variety of shapes and sizes
results in boiling over very large range
most of them are useful, but used for very different purposes
therefore we need to separate the oil into fractions
as the boiling point of crude oils increases…
- the fractions get darker in colour
- fractions get more viscous
what’s the use and position of refinery gases?
1 - lowest , light colour and low viscosity
fuel for home cooking
what’s the use and position of gasoline?
2
fuel for cars
what’s the use and position of kerosene?
3
fuel for aircraft
what’s the use and position of diesel?
4
fuel for trains
what’s the use and position of fuel oil?
5
fuel for ships
what’s the use and position of bitumen?
6 - highest/ last
making roads
what part is the hottest and coldest part of the fractional distillation?
hotter at bottom
colder at top
how does fractional distillation work?
- heated crude oil vapours enter the column
- vapours rise until they reach their boiling point where they condense
- different vapours condense at different heights due to their different boiling points
- similar vapours condense together as a fraction
what is the order of fraction from low BP to high BP?
refinery gases
gasoline
kerosene
diesel
fuel oil
bitumen
what are alkanes?
hydrocarbons made of molecules C & H held together by covalent bonds
what is the general formula for alkanes?
C(n)H(2n+2)
what is the formula for methane?
CH4
what is the formula for ethane?
C2H6
what is the formula for propane?
C3H8
what is the formula for butane?
C4H10
what is the formula for pentane?
C5H12
what’s the structural formula for butane?
CH3 CH2 CH2 CH3
what’s the empirical formula for butane?
C2H5
alkanes are a …
homologous series of organic molecules
why are alkanes a homologous series?
as they have similar chemical reactions, trends in physical properties, same general formula
what are isomerism with alkanes?
isomers are the same molecular formula just different structural formula