# Are acids and bases always aqueous? [closed]

I am tying to determine if an acid is a liquid or aqueous solution? Please can some one enlighten me?

There are varying definitions of"acid" (or "base") depending on solvent system; some do not involve water at all. For example, there are Brønsted–Lowry acids (proton donors) and Lewis acids (electron acceptors), though the Arrhenius definition is based on aqueous solutions dissociating into $\ce{H+}$ (acid) or $\ce{OH-}$ (base) ions.