pyrosulfuric acid

noun

, Chemistry.

1. an oily, hygroscopic, corrosive liquid, H 2 S 2 O 7 , that, depending on purity, is colorless or dark brown: used chiefly as a dehydrating agent in the manufacture of explosives and as a sulfating or sulfonating agent in the manufacture of dyes.

pyrosulfuric acid

/ pī′rō-sŭl-fyr′ĭk /

1. A heavy, oily, colorless to dark brown liquid produced by adding sulfur trioxide to concentrated sulfuric acid. It is used in petroleum refining and the manufacture of explosives. Chemical formula: H 2 S 2 O 7 .

Word History and Origins

Origin of pyrosulfuric acid¹

First recorded in 1870–75