Organic chemistry Flashcards
What is crude oil and where does it come from
Is a finite resource found in rocks
Is the remains of an ancient biomass consisting mainly of plankton
that was buried in mud
What is crude oil made out of
mixture of a very large number of compounds
Most of the compounds are hydrocarbons
Most of these saturated
hydrocarbons are alkanes.
What is the process of fractional distillation
1)crude oil enters fractionating column which is very hot at the bottom and cool at the top(temperature gradient)
2)It is heated so vapours rise
3)Vapours of hydrocarbons with very high boiling points will immediately condense into liquid lower down and are collected at the bottom of the column
Vapours of hydrocarbons with low boiling points will rise up the column and condense at the top
different fractions condense at different heights according to their boiling points and are tapped off as liquids
The fractions containing smaller hydrocarbons are collected at the top of the fractionating column as gases
The fractions containing bigger hydrocarbons are collected at the lower sections of the fractionating column
How do you determine whether a hydrocarbon is useful as a fuel
Based on its properties
What are the 3 properties
Flammability-How easily it burns
Boiling point-temperature at which it boils
Viscosity-How thick it is
What are the properties of a long chain molecule
Low flammability
High boiling point
High viscosity
What are the properties of a short chain molecule
High flammability
Low boiling point
Low viscosity
Why does boiling point increase as molecules get bigger
The intermolecular forces of attraction between the molecules becomes greater
Why are hydrocarbons used as fuels
burnt so that they can be used as fuel, when they react with oxygen they produce energy
Complete combusiton-carbon dioxide and water produced
What are alkanes and what is the molecular formula for them
Saturated hydrocarbons- single bonds only
CnH2n+2
What are alkenes and what is the molecular formula for them
Unsaturated hydrocarbons-double bound
CnH2n
What are the first 4 alkanes and alkenes
Methane Ethane Propane Butane
Ethene propene butene Pentene
What useful products come from the separation of crude oil
Fuels- Petrol,diesel,kerosene
Feedstock-Frcations form raw material for other processes and the production of other substances
Many useful materials-solvents, lubricants, polymers,detergents
What is cracking
Breaking down larger hydrocarbons to produce smaller more useful molecules.
What are the two types of cracking
catalytic cracking and steam cracking.
