an acid, HCrO, existing only in solution or known in the form of its salts
See chromic acid in American Heritage Dictionary 4
noun
A corrosive, oxidizing acid, H2CrO4, occurring only as salts or in solution.
The anhydride of chromic acid, CrO3, a purplish crystalline material that reacts explosively with reducing agents and is used in chromium plating, as an oxidizing agent, and to color glass and rubber.