Lewis Structure in identifying Acid or Base

[Irma Ramos 2I]

How do we know whether or not something is an acid or base from drawing the Lewis structure??

[Yang Chen 2E]

If you're looking at lewis structures, you can tell which one is an acid or base by following the lewis definition of acids/bases. Lewis acids will have electron pairs to donate while lewis bases will have electron pairs they can receive.

[EveEmm3D]

Lewis bases will have lone pairs of electrons that can be used to bond to another atom, like in NH3 for example, where N has a lone pair. Lewis acids will be "electron deficient" species, species that could accept more electrons. Some examples are BF3 where B has an incomplete octet, Pt4+, Na+.