pyrosulfuric acid
noun
py·ro·sulfuric acid
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Definition of pyrosulfuric acid
: an unstable, crystalline acid H2S2O7 that is usually handled commercially as a thick oily fuming liquid, that is formed by the union of sulfur trioxide with sulfuric acid, that is a chief component of fuming sulfuric acid, and that is converted to sulfuric acid when mixed with water
— called also disulfuric acid
— compare oleumKeep scrolling for more