What is a Co-ordinate or Dative bond?

A bond in which both electrons of the shared pair are contributed by one of two atoms such a bond is called  a co-ordinate bond.
Co-ordinate bond or Dative bond

The Reimer-Tiemann reaction: Reaction and its Mechanism

Reimer-Tiemann Reaction Phenols on reaction with chloroform in the presence of sodium hydroxide (or potassium hydroxide) solution give hydro...