Question

What is coordinate bond give example with dot diagram

Answer 1

A coordinate bond is a type of covalent bond where both of the electrons that form the bond originate from the same atom (more generally, a "dative" covalent bond

A coordinate covalent bond, also known as a dative bond or coordinate bond is a kind of 2-center, 2-electron covalent bond in which the two electrons derive from the same atom.

Let's take the example of BF3 and NH3.
BF3 is an electron deficient compound because it has only 6elctrons around it .It needs 2more to satisfy it's octet.Now NH3 is an electron rich compound as Nitrogen has a lone pair of electrons on it . Now THIS lone pair of electrons can be donated to BF3 to satisfy is octet. This bond formed is called a coordinate covalent bond (IT is denoted by an arrow)

NH3 +BF3. =. NH3--->BF3