Which of the following chemical species possess a coordinate bond?H2ONH3H3O+OH–

The chemical species that possess a coordinate bond is H3O+.

Here's why:

A coordinate bond (also known as a dative covalent bond) is a covalent bond (a shared pair of electrons) in which both electrons come from the same atom.

1. H2O (Water): The oxygen atom in water forms two regular covalent bonds with two hydrogen atoms. So, it doesn't have a coordinate bond.

2. NH3 (Ammonia): In ammonia, the nitrogen atom forms three regular covalent bonds with three hydrogen atoms. So, it doesn't have a coordinate bond either.

3. H3O+ (Hydronium ion): In the hydronium ion, one of the hydrogen atoms is donated by another water molecule, forming a coordinate bond with the oxygen atom. So, H3O+ does have a coordinate bond.

4. OH– (Hydroxide ion): In the hydroxide ion, the oxygen atom forms a regular covalent bond with a hydrogen atom. So, it doesn't have a coordinate bond.

Therefore, out of H2O, NH3, H3O+, and OH–, only H3O+ possesses a coordinate bond.