Org Chem Lec M7

• Hydrocarbons

  contain only carbon and hydrogen atoms
• Saturated

  have only C-C and C-H single bonds and thus contain the maximum possible number of hydrogens per carbon
• Straight-chain alkanes

  Carbons are connected in a row
• Branched-chain alkanes

  compounds with branched carbon chains
• Alkyl group

  the partial structure that remains if a hydrogen atom is removed from an alkane; replacing the -ane with -yl
• Natural gas

  consists chiefly of methane but also contains ethane, propane and butane
• Petroleum

  a complex mixture of hydrocarbons that must be separated into fractions and then further refined before it can be used; fractional distillation
• Alkanes show regular increases in both boiling point and melting point as molecular weight increases
• Branching lowers an alkane's melting point
• Alkanes are sometimes referred to as paraffins, a word derived from the Latin parum affinis, meaning "slight affinity"
• Reaction of Alkanes: Combustion

  the reaction of an alkane with O2 occurs during combustion in an engine or furnace when the alkane is used as a fuel

  reactants: ALKANE + OXYGEN

  products: CARBON DIOXIDE, WATER, HEAT
• Reaction of Alkanes: Halogenation

  when a mixture of the two is irradiated with ultraviolet light (denoted hv); sequential replacement