Fractional Distillation - Crude oil / cracking

What happens when Crude oil is heated?

It turns into vapour which then rise through a column which is hot at the top and cool at the bottom

How does fractional distillation work?

Different hydrocarbons have different boiling points due to the chain lengths so they all go in different columns

When does the vapour condense?

When it reaches the part of the column below it’s boiling point

Where do small molecules condense?

At the top of the column

Where do large molecules condense?

Further down the column

What is cracking?

Large useless hydrocarbons are cracked to form smaller more useful hydrocarbons

What is needed for cracking?

High pressure/ temperature and a catalyst