## Chemistry: The Molecular Science (5th Edition)

$PH_3$ is a Lewis base.
Drawing the Lewis structure, we can see that, the central atom has a lone pair of electrons, therefore, this compound can behave as a Lewis base. For example, when reacting with water: $PH_3(aq) + H_2O(l) \lt -- \gt P{H_4}^+(aq) + OH^-(aq)$ The lone pair is donated to create a bond between the molecule and one hydrogen from the Lewis acid: $H_2O$. ------