Fractional Distillation

Crude oils =) not useful , mixture of hydrocarbons

We can fractionally distill crude oil to get useful hydrocarbons for uses such as : bitumen …

Van Der Waals forces “ break down during vaporization + reform when condensing - no covalent bond broken.

Stages of Fractional distillation

1. Crude oil is heated up to 350 *c and the vaporized oil goes into the bottom of column and it rises up through the trays

2. The largest hydrocarbon don’t vaporized because their boiling pt is too high

3. Crude oil vapours goes up the column → it gets coolers and creat a temperature gradient

4. Because of the boiling pt of alkanes increases, as the molecules get bigger → each fractions condense at different temperatures. The fractions are drawn off at different levels in the column.

5. The hydrogcarbons with the lowest boiling pt DONT CONDENSES → drawn off as gases at the top of the column.

6. Largest hydrocarbon at the bottom / Smallest hydrocarbon at the top

7. Van Der Waals forces break during vaporization and reforms when condensing.

Fractions = group of chemicals with similar boiling points

Uses of crude oil fractions

gases → camping gas

Petrol

Waxes & grease → candles & lubricants

Bitumen → roofing , road surfacing