Fractional Distillation Flashcards
Order of fractions
- Bitumen
- Fuel oil
- Diesel
- Kerosene
- Petrol
- Refinery gases
What is a use for petrol?
Fuel for cars
What is a use for bitumin?
Tar for roads
What is a use for fuel oil?
Fuel for ships
What is a use for diesel?
Fuel for buses
What is a use for kerosene?
Fuel for aircraft
What is a use for refinery gases?
Domestic heating
Process of fractional distillation
1 Crude oil is vaporised
2 Vaporised oil enters fractionating column
3 Fractions rise up the column, which is hotter and the bottom and cooler at the top
4 Fractions condense at their boiling point and are collected
What is crude oil
It is a mixture of hydrocarbons
Are fractions pure or mixture?
Mixture because they have a range of boiling points
What is a fraction
A group of compounds with similar boiling points
What are hydrocarbons
Hydrocarbons are made up of hydrogen and carbon only
Describe the trend in boiling points of the alkanes
As molecules become bigger, the strength of the intermolecular forces of attraction between them increases. The boiling points of the alkanes therefore increase in a regular way, as more energy is required to break the intermolecular forces.
The properties of smaller (higher up fractionating column) molecules
Low boiling point
Low viscosity
Colourless
Properties of large molecules
High boiling point
High viscosity
Dark coloured
