Organic Chemistry Flashcards
What is a hydrocarbon?
Atom of carbons and hydrogen bonded
What is the formula for alkanes?
CnH2n+2
Name the alkanes and their formulas
Methane CH₄
Ethane C₂H₆
Propane C₃H₈
Butane C₄H₁₀
What are the features of alkanes?
- Saturated (all carbon atoms have 4 single bonds)
What is crude oil?
Finite resource produced by build up of pressure on biomass like plankton underground.
What are the trends as you go down the alkene group?
Boiling point rises, viscousity rises, flammability falls
What is combustion?
Burning with oxygen, if enough it results in complete combustion
What is the technique used to separate crude oil?
fractional distillation
Explain the method of fractional distillation.
Feed crude oil into chamber as a gas, it should enter the fractionating column, which gets cooler at the top. The gases should condense at different points due to diff BPs. Longer chain collected at the bottom and shorter at top.
What are longer and shorter chain molecules, collected in fractional distillation, used for?
Longer: Heavy fuel oil (less flammable)
Shorter: Petrol, diesel and kerosene (more flammable)
What is cracking used for?
To breakdown longer hydrocarbons collected at the bottom of the fractionating column
What are the 2 types of cracking?
Steam
Catalytic
Explain steam cracking.
Heat and vaporize the molecule, pass this vapor through steam, then heat at high temps. Should split the hydrocarbon.
Explain catalytic cracking.
Heat and vaporize the molecule, pass this vapor through hot powdered aluminium oxide, then heat at high temps. Should split the hydrocarbon.
What are the products of cracking?
Long chain molecule–> Shorter alkane + alkene
