CHAPTER 9 Flashcards
where is crude oil found
rocks
how is crude oil made
remains of sea life were buried in mud and layers of rock build up on top
this create the high pressure and temperature needed for crude oil
what conditions are needed for crude oil to form 3
no oxygen
high temperature
high pressure
what is crude oil
a mixture of different carbon compounds
what is a hydrocarbon
compounds containing carbon and hydrogen
what is a fraction
different substances with similar boiling points found in crude oil
formula and name of first alkane
methane CH4
formula and name of second alkane
ethane C2H6
formula and name of third alkane
propane C3H8
formula and name of fourth alkane
butane C4H10
how can you describe alkanes
saturated hydrocarbons
what is a saturated hydrocarbon
it contains as many hydrogen atoms as possible in each molecule
general formul of alkane
Cn H(2n+2)
which hydrocarbon burns and ignites best
short chain hydrocarbons
as the chain length increases, what happens to the boiling point of a hydrocarbon
it increases
as the chain length increases what happens to the velocity of a hydrocarbon
it decreases
what is the volality of a hydrocarbon
the tendency of a substance to turn into a gas
as the chain length increase what happens to the viscosity of a hydrocarbo
it gets thicker
higher viscosity
what is the viscosity of a substance
how easily it flows
what do the properties of each fraction depend on
the size of the hydrocarbon molecules in it
process of fractional distillation of crude oil
it is heated at the bottom of a tall column which is cooler at the top
the gases move up the column when they reach their boiling point they condense at the cooler temperature
they condense at different levels so can be connected
what are the products of complete combustion of hydrocarbons
carbon dioxide and water
when does incomplete combustion occur
when there isn’t enough oxygen
what happens to the hydrocarbon when complete combustion occurs
they are oxidised to form the products
what is produced when incomplete combustion occurs
carbon monoxide
how to tell that a hydrocarbon is an alkane
it has a c-c single bond
two tests for water
turns cobalt chloride paper pink
turns white anhydrous copper sulfate blue
why are hydrocarbons cracked
the longer chainlengths aren’t in high demand but the shorter ones are so they are broken down to form these desirable chainlengths
process of cracking
the fraction is heated to vaporise the hydrocarbons the vapour is then heated to a very high temperature
thermal decomposition takes place turning larger molecules into smaller molecules
how to tell that a hydrocarbon is alkene
has a c=c double bond
are alkenes saturated or unsaturated
unsaturated, compared to alkenes they have 2 less hydrocarbons for the carbon to bond to
why are alkenes more reactive
the double bond opens up to form a single bond and allow the carbon to bond to other atoms
general formula for alkenes
Cn H2n
first four alkenes
ethene
propene
butene
pentene
what happens when an alkene reacts with oxygen
if there is enough oxygen it will undergo complete combustion however alkenes are very likely to undergo incomplete combustion
what is produced when an alkene undergos incomplete combustion
carbon carbon monoxide carbon dioxide and water
what does the flame look like of something undergoing incomplete combustion
it will burn a smokey yellow flame
what is the test for an unsaturated hydrocarbon
it turns orange bromine water colourless
