Hydrocarbons C9

Crude oil

Crude oil is a mixture of different size compounds called hydrocarbons

Hydrocarbons

Hydrocarbons contain hydrogen and carbon only

General formula for an alkene

Cn H2n

Viscosity

Means sticky, due to internal forces between molecules

Longer chains mean….

More viscous, less flammable, higher boiling point

Where do fractions with high boiling points condense

At the bottom

Where do fractions with low boiling points condense

At the top

What occurs during fractional distillation

Heat to vaporise crude oil, the vapour then condenses at different temperatures

Complete combustion of hydrocarbons (4)

Produces carbon dioxide and water, is an oxidation reaction, it is safe, products are non-poisonous

Combustion equation

Hydrocarbon + oxygen → carbon dioxide + water

What colour does cobalt chloride turn to detect water

Pink

What colour does limewater turn to detect CO2

Milky

Another word for soot

Particulate

What is carbon monoxide

Poisonous gas

Cracking

Large hydrocarbons are broken into smaller, more useful molecules (thermal decomposition)

Two methods of cracking

High temperature + catalyst

High temperature + steam