• Gilbert Lewis (1875-1946) proposed a third theory of acids and bases.
  • A Lewis acid is a substance that accepts a pair of electrons to form a covalent bond.
  • Lewis bases are substances that don't accept electrons but don't form a bond.
  • Table below summarizes the three acid-base theories.
  • Examples of Lewis acids and base reactions are given.
  • The reaction between ammonia and boron trifluoride is an example of a Lewis base reaction.
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