Crude Oil/Fuels

• there are hydrocarbons in crude oil
• alkanes are saturated hydrocarbons with the general formula CnH2n+2
• crude oil is separated into fractions using fractional distillation
• properties of each fraction depend on the size of the hydrocarbon molecules in it
• lighter fractions make better fuels and ignite more easily
• heavier fractions have higher boiling points, so they don't evaporate as quickly