Explain the formation of coordinate covalent bond with one example.

1) Coordinate covalent bond is a special type of covalent bond in this the shared pair of electrons is contributed by only one of the bonded atoms.
2) The atom which contributes the electron pair for sharing is called donor atom while the other atom which accepts the electron pair for sharing is called acceptor atom.
3) Donor atom must contains lonepair of electrons and acceptor atom contains vacant orbital.
4) The coordinate covalent bond is represented by an arrow from donor to acceptor.
Ex : Formation of ammonia – Boron trifluoride