Organic chemistry Flashcards
What is crude oil
A fossil fuel formed in underground rock. It is a mixture of hydrocarbons
How is crude oil formed
Tiny marine plants and animals died and were buried. Over time they were covered by layers of silt and sand
Over millions of years, the remains were buried deeper and deeper. The enormous heat and pressure turned the remains into oil and natural gas
Today, we drill down through layers of sand, silt and rock to reach the oil and natural gas deposits
What is a hydrocarbon
A compound consisting of entirely hydrogen and carbon atoms
What is an alkane
A saturated hydrocarbon
What are the properties of alkanes
Only have single bonds
Have the general formula CnH2n+2
They are a homologous series (same general formula and similar properties)
What are the first 4 alkanes
Methane (CH4)
Ethane (C2H6)
Propane (C3H8)
Butane (C4H10)
How does fractional distillation work
Crude oil is heated so it turns into a vapour
Vapours rise
Vapours cool and condense at different boiling points
The vapours cool because it is hotter at the bottom and cooler at the top
After the vapours condense, each fraction contains a mixture with similar boiling points
Fractions at the bottom have high boiling points and smaller molecules. Vice versa for the top
What is viscosity
How thick a liquid is
What is flammability
How easily a substance catches on fire
What happens when you go down the fractions (top to bottom)
Boiling point increases
Viscosity decrease
Flammability decreases
What is complete combustion
When a substance burns with a good supply of oxygen
Hydrocarbon + Oxygen → Carbon Dioxide + Water
What is an alkene
An unsaturated hydrocarbon
What are the properties of alkenes
Contain a double bond
Have the general formula CnH2n
They are a homologous series (same general formula and similar properties)
What are the first 4 alkenes
Ethene (C2H4)
Propene (C3H6)
Butene (C4H8)
Pentene (C5H10)
What is cracking
The thermal decomposition of longer hydrocarbons into smaller hydrocarbons
Long alkane → alkane + alkene