c7 organic chemistry Flashcards
crude oil
a finite resource found in rocks, crude oil is the remains of ancient biomass consisting of mainly plankton. Over millions of years, pressure changes resulted in the production of oil
composition of crude oil
a mixture of compounds. Most compounds in crude oil consist of hydrocarbons
example of a hydrocarbon
methane
alkanes
most of the hydrocarbons in crude oil are alkanes. Different alkanes consist of different numbers of carbon atoms
why are alkanes a homologous series
because they have similar properties
rule when drawing alkanes
- carbons always have 4 bonds
- hydrogen atoms always have 1 bond
general formula for alkanes
CnH2n+2
propane
C3H8
Butane
C4H10
methane
CH4
ethane
C2H6
alkenes
more reactive than alkanes, said to be unsaturated because they contain double bonds
bromine water test
- bromine water + alkene
= solution will turn colourless
why does the bromine water test become colourless
because alkenes are more reactive than alkanes, the will react with bromine water and cause it to become colourless
hydrocarbons as fuels
longer chain hydrocarbons are not very flammable, so they are broken down into shorter chain
cracking
the process by which hydrocarbons are broken down into shorter chain
catalytic cracking
takes place at a high temp and uses a catalyst
2 methods of cracking
catalytic and steam cracking
steam cracking
steam cracking takes place at high temperatures and uses steam
product of cracking
- alkanes and alkenes
- alkanes are used as fuels
what is an alkane
saturated hydrocarbons, their carbon atoms are joined together by single bonds - unreactive apart from reaction with oxygen
what is an alkene
contain carbon double bonds
