Crude oil and fuels

9.1 Hydrocarbons

• Organic compounds are used as fuel to run cars, to warm homes, and to make electricity
• Fuels are sig. because they keep you warm and on the move, so when oil prices rise, it affects everyone. Countries making crude oil can affect the countries economy by their oil £
• Crude oil's found in rocks and was made millions of years ago from remains of ancient sea animals, plants and plankton, that were buried in mud. Over time, multiple layers of rock laid on the materials, creating the conditions (high pressure, temp, no O2) to make crude oil
• Crude oil's a dark, smelly mixture made of many different carbon compounds
• Most of the compounds in crude oil are hydrocarbons - they contain only hydrogen and carbon atoms
• Crude oil's seperated into fractions to increase its use, by distillation
• To distillate crude oil heat it until it boils and the different fractions vaporise between a temp. gradient. The the vapours will be collected and condensed
• Most hydrocarbons in crude oil are alkanes, saturated hydrocarbons. All carbon-carbon bonds are single covalent bonds, meaning they have as many hydrogen atoms as possible in each molecule

      General formula for alkanes :    C_nH(_2n+2)

9.2 Fractional distillation of oil

• Short chain molecules are more useful as they make good fuels that ignite easily when burnt, with less smoky flames - they're flammable

• Fractional distillation allows crude oil to seperate hydrocarbons w/ similar b.p.ts, called fractions. The hydrocarbons have molecules w/ similar no.s…