phthalic

Phthal"ic, a. Etym: [Naphthalene + -ic.] (Chem.) Defn: Pertaining to, or designating, a dibasic acid obtained by the oxidation of naphthalene and allied substances. Phthalic acid (Chem.), a white crystalline substance, C6H4.(CO2H)2, analogous to benzoic acid, and employed in the brilliant dyestuffs called the phthaleins.

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