prelim-second sem

Cards (12)

  • •Organic Chemistry is the study of carbon compounds. The word “organic” was originally used by eighteenth-century chemists to describe substance obtained from living sources- plants and animals.
  • •This romantic notion was disproved in 1828 by Friedrich Wohler, a German chemist who prepared urea, an organic compound, from the reaction between the inorganic compounds lead cyanate and aqueous ammonia.
  • •Carbon can form more compounds than any other element because carbon atoms are able not only to form single, double, and triple carbon-carbon bonds, but also to link up with each other in chains and ring structures.
  • •The branch of chemistry that deals with carbon compounds is organic chemistry.
  • •A functional group is a group of atoms that is largely responsible for the chemical behavior of the parent molecule.
  • All organic compounds are derived from a group of compounds known as hydrocarbons because they are made up of only hydrogen and carbon.
  • Aliphatic hydrocarbons do not contain the benzene group, or the benzene ring, whereas aromatic hydrocarbons contain one or more benzene rings.
  • The alkanes are known as saturated hydrocarbons because they contain the maximum number of hydrogen atoms that can bond with the number of carbon atoms present.
  • Structural isomers are molecules that have the same molecular formula, but different structures.
  • Alkanes such as the structural isomers of butane are described as having the straight chain or branched chain structures.
  • The first four alkanes (methane, ethane, propane, and butane have nonsystematic names).
  • An alkane less one hydrogen atom is an alkyl group. For example, when a hydrogen atom is removed from methane, we are left with the CH3 fragment, which is called a methyl group.