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