Crude Oil and Hydrocarbons

Crude oil is a fossil fuel that formed from ancient biomass - mainly tiny sea creatures called plankton that died millions of years ago. It's a finite resource, which means once we use it all up, it's gone forever.

The formation process is fascinating: dead plankton fell to the sea floor, got buried under layers of mud and sediment, then over millions of years, heat and pressure transformed them into the thick, black liquid we drill for today. Raw crude oil contains loads of different compounds mixed together, mostly hydrocarbons (molecules made only of carbon and hydrogen atoms).

Alkanes are one important family of hydrocarbons found in crude oil. They're called saturated because all their carbon atoms are joined by single bonds. You can work out any alkane's formula using C₍ₙ₎H₍₂ₙ₊₂₎ - where n is the number of carbon atoms. The first four alkanes are methane (CH₄), ethane (C₂H₆), propane (C₃H₈), and butane (C₄H₁₀).

Key Insight: The length of hydrocarbon chains affects their properties - longer chains are more viscous (thicker), less volatile (harder to turn into gas), and have higher boiling points than shorter chains.