Cr2SO43

Cr2SO43 is commonly written to denote chromium(III) sulfate, Cr2(SO4)3, an inorganic salt composed of chromium in the +3 oxidation state and sulfate anions. In practice, the compound is typically encountered as hydrates rather than anhydrous material, such as Cr2(SO4)3·xH2O, and the hydrated forms are more stable under ordinary conditions. When dissolved in water, Cr3+ ions are present as aquated species, for example [Cr(H2O)6]3+, and the solution can undergo hydrolysis depending on pH.

Preparation of chromium(III) sulfate can be achieved by reacting chromium oxide or hydroxide with hot concentrated sulfuric acid, followed by crystallization of the salt. An alternative route is the direct sulfonation of chromium-containing materials under acidic conditions. The compound is a salt and forms various hydrates that are soluble in water, providing a source of Cr3+ for chemical synthesis or industrial processes.

Applications of Cr2(SO4)3 include use as a chromium source for leather tanning, where chromium(III) salts cross-link collagen fibers in hides. It is also employed as a mordant in dyeing and printing processes and acts as a precursor to other chromium(III) compounds used in catalysis and material synthesis. In solution chemistry, Cr2(SO4)3 provides Cr3+ for coordination chemistry studies and for preparing chromium-based complexes.

Safety and handling: chromium(III) sulfate is a relatively less toxic form of chromium compared with hexavalent chromium compounds, but it should still be handled with standard laboratory precautions. Avoid inhalation of dust, and prevent release to the environment. Waste should be disposed of according to applicable regulations for chromium salts.