BRAINCAKEAlkanes
Revision notes for Alkanes in Edexcel Chemistry (8CH0). Every lesson in BrainCake comes with R.E.C.I.P.E. recall steps, a quick check and spaced reviews.
- AlkanesAlkanes are saturated hydrocarbons: they contain only carbon and hydrogen, joined by single covalent bonds.
- Alkanes from Crude OilCrude oil is a mixture of hydrocarbons, mostly alkanes, with chains from one to over fifty carbon atoms.
- CrackingFractional distillation gives more of the long-chain fractions than are needed, and not enough of the short-chain fractions such as petrol.
- ReformingReforming converts straight-chain alkanes into branched-chain alkanes and cyclic hydrocarbons (cycloalkanes and arenes such as benzene).
- Combustion of AlkanesAlkanes are used as fuels because their combustion is very exothermic and they are easy to transport and store.
- Oxides of SulfurFossil fuels such as coal, crude oil and natural gas contain small amounts of sulfur compounds as impurities.
- Oxides of NitrogenOxides of nitrogen, written together as NOx, are pollutants from vehicle engines and power stations.
- Catalytic ConvertersA catalytic converter is fitted to a vehicle exhaust to change the most harmful pollutants into less harmful gases.
- Alternative FuelsMost of the world's energy still comes from fossil fuels.
- BiofuelsA biofuel is a fuel made from biomass: plant or animal material from recently living organisms.
- Biofuels vs Fossil FuelsBiofuels are often described as better for the environment than fossil fuels, but the comparison needs care.
- Bond BreakingA covalent bond is a shared pair of electrons.
- Free-Radical Substitution of AlkanesAlkanes react with chlorine or bromine in ultraviolet (UV) light.
- Further SubstitutionFree-radical substitution does not stop at one substitution.
On the specification
- Topic 6B: Alkanes