Organic Chemisty - Hydrocarbons And Crude Oil Flashcards
What is a hydrocarbon
Any molecule formed with carbon and hydrogen atoms only
What is an alkane
Simplest form of of hydrocarbon. Chains of carbon atoms surrounded by hydrogen atoms.
What does it mean that alkanes are saturated
All atoms have formed bonds with as many other atoms as they can
How many carbon atoms does butane, propane, ethane and methane have
Methane has 1
Ethane has 2
Propane has 3
Butane has 4
What is the general formula for alkanes
CnH2n+2
How does the length of the carbon chain of a hydrocarbon effect its viscous (runnyness)
Shorter, runneyer
How does the length of the carbon chain of a hydrocarbon effect boiling point and flamidity
The shorter, the lower the boing point
The shorter, the more flammable
What is the equation for complete combustion of a hydrocarbon
Hydrogen + oxygen = c20 + water vapour
What is ment by complete combustion
All the carbon atoms are completely oxidized
What is crude oil
Mixture of different compounds. Formed from the remains of plants and animals mainly plankton that was burroed in mud.
Most of the compounds are hydrocarbons and the majority of them are alkanes
What are the right conditions for crude oils to form and how do we extract it
High temperature and pressure.
Drilled up from the rocks.
How is crude oil separated and what are the groups of hydrocarbons called that condense at similar temperatures
Fractional distillation
Fractions
What is crude oil use for
Fractions can be processed for fuel for most modern transport
Petrochemical industry uses some as a feedstock to make new compounds eg polymers, solvents lubricants and detergents.
What’s an organic compound
Compounds containing carbon atoms
Carbon atoms bind together to form different groups called what
Homologous series
Contains similar compounds that have the same general formula and many properties in common.
Eg alcohols and alkanes are homologous series
What is cracking
Where long chained hydrocarbons are turned into smaller ones
What are the products of cracking
Fuels and things like ethane wich is used for making plastics and paraffin
How does cracking work
Cracking is a thermal decomposition reaction.
- Heat long chain hydrocarbon to vaporise.
- In catalytic cracking the vapour is passed over a hot powdered catalyst eg aluminium oxide. They split apart on the surface of the spects of catalyst.
In steam cracking the vapour can be mixed with steam and heated to a high temp. This also leads to thermal decomposition of the long chains
What are most of the products of cracking
Unsaturated hydrocarbons called alkenes
