As these examples show, acids (in the colloquial sense) can be solutions or pure substances, and can be derived from acids (in the strict sense) that are solids, liquids, or gases.
æz ðiːz ɛɡzˈæmpəlz ʃˈoʊ, ˈæsɪdz ɪnðə kəlˈoʊkwɪəl sˈɛns kæn biː səlˈuːʃənz ɔːɹ pjˈʊɹ sˈʌbstənsᵻz, ænd kæn biː dᵻɹˈaɪvd fɹʌm ˈæsɪdz ɪnðə stɹˈɪkt sˈɛns ðæt ɑːɹ sˈɑːlɪdz, lˈɪkwɪdz, ɔːɹ ɡˈæsᵻz.