Organic Chemistry Flashcards
Where is crude oil made from?
Crude oil is made from the fossilised remnants of ancient plankton.
Where is crude oil found?
Crude oil is found in rocks and is used to produce other important chemicals.
What is crude oil?
Crude oil is a mixture of different compounds that are not chemically combined. Most are hydrocarbons.
What are hydrocarbons?
Hydrocarbons are molecules only made up of carbons and hydrogen atoms. They can differ in size, which may change the property of the hydrocarbon.
What are the most important properties of hydrocarbons?
- Hydrocarbons with longer chains have higher boiling points.
- Hydrocarbons with longer chains have a higher viscosity (flow thick).
- Hydrocarbons with longer chains are less flammable.
What are alkanes?
Carbon atoms that bond to four atoms (hydrogen or carbon).
These are known as saturated hydrocarbons as their bonds with other atoms are single bonds.
What are the uses of alkanes?
Alkanes have low reactivity, but combust quite well, making them useful as fuels.
What is the general formula for an alkane?
CnH(2n+2)
What are the four smallest alkanes?
Methane - CH4
Ethane - C2H6
Propane - C3H8
Butane - C4H10
What is fractional distillation?
Fractional distillation is the process of separating crude oil into groups of hydrocarbons with similar numbers of carbon atoms.
How does fractional distillation work?
Evaporation - crude oil vapour is put into a fractioning column at the bottom and rises upwards.
Condensation - Temperature is highest at the bottom, long chains are collected at the bottom as liquids.
Collection - Once collected, they are processed to create end products like fuels.
What is the homologous series?
Different organic compounds as carbon atoms can form families of similar compounds.
What happens if hydrocarbon burns with a lack of oxygen?
Carbon monoxide can be created:
2C + O2 = 2CO
- Odourless
- Toxic
- Colourless
What happens if hydrocarbons burn with plenty of oxygen?
Complete combustion
- Release of energy
- Oxidation of carbon and hydrogen to create carbon dioxide and water.
Why don’t heavy fractions of crude oil make good fuels?
- Don’t ignite easily
- Have low volatility
- Have high boiling points